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Changes to moderation procedures
by James Mitchell Sept. 28, 2025

Sept. 28, 2025

Hi all, We've made a small update to moderation settings in response to recent spam: * First posts from new members will be held for review. Once approved, the moderation flag will be removed. * All posts from non-members will continue to be held for moderation. A few existing members currently have moderation enabled. You may experience brief delays while these changes take effect—thank you for your patience. If you believe your messages are being held in error, please contact the list owners at tz-owner(a)iana.org<mailto:tz-owner@iana.org>. Kind regards, James Mitchell IANA

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List moderation
by Kim Davies Sept. 24, 2025

Sept. 24, 2025

Hi folks, Our team have removed the list subscriber that flooded the list with emails in the last few minutes, and have put some emergency moderation in place until we can confirm it has died down. Apologies for the noise. kim

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Prevent spam
by stan＠ulbrych.org Sept. 24, 2025

Sept. 24, 2025

Hello, I just received a barrage of emails (over 50) due to spam messages, I suggest the list owners look into first posts requiring approval before they are published. This is done for example in the Python docs list, and allows for such spam to be prevented. Best Regards, Stan Ulbrych

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List moderation
by Kim Davies Sept. 24, 2025

Sept. 24, 2025

Hi folks, Our team have removed the list subscriber that flooded the list with emails in the last few minutes, and have put some emergency moderation in place until we can confirm it has died down. Apologies for the noise. kim

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CRA auditor in BC checked commute route and distance in Toronto at rush hour BC time
by Brian Inglis Sept. 7, 2025

Sept. 7, 2025

How Google Maps helped one Toronto commuter beat traffic - and the tax collector: https://www.cbc.ca/news/canada/british-columbia/traffic-relocation-tax-cour… CRA auditor in BC checked commute route distance in Toronto at rush hour BC time! -- Take care. Thanks, Brian Inglis Calgary, Alberta, Canada La perfection est atteinte Perfection is achieved non pas lorsqu'il n'y a plus rien à ajouter not when there is no more to add mais lorsqu'il n'y a plus rien à retrancher but when there is no more to cut -- Antoine de Saint-Exupéry

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TZLOAD_FROMENV flag used incorrectly
by Dag-Erling Smørgrav Aug. 31, 2025

Aug. 31, 2025

tzset_unlocked() calls zoneinit() with TZLOAD_STRINGS | TZLOAD_FROMENV regardless of whether name actually came from the environment. If name is null, zoneinit() will use TZDEFAULT instead, but will incorrectly consider that to be tainted, and unnecessarily perform an access check before trying to open it. That is luckily harmless in unmodified tzcode, but I would still prefer if TZLOAD_FROMENV were only set when actually true; see attached patch. DES -- Dag-Erling Smørgrav - des(a)des.no

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[PROPOSED] Update tz-link for FTP, Go, Levine proposal
by Paul Eggert Aug. 30, 2025

Aug. 30, 2025

* tz-link.html: Remove links to projects that seem to be dead: MINIX, tziCal, tzdist-bis, Australian Parliamentary Library pub. Remove ftp: links as modern browsers don’t support them; instead, just mention FTP (and rsync, while we’re at it). Go seems to have fixed its 32-bit time_t bug. Cite British Sleep Society position paper on DST, and move the medical citations to a new list. Update citation to Judah Levine’s proposal to use 13-second leap smears every decade, as a substitute for leap seconds. --- tz-link.html | 115 +++++++++++++++++++++++++++------------------------ 1 file changed, 60 insertions(+), 55 deletions(-) diff --git a/tz-link.html b/tz-link.html index 76566224..669a3cb8 100644 --- a/tz-link.html +++ b/tz-link.html @@ -84,7 +84,6 @@ title="Berkeley Software Distribution">BSD</abbr></a>, <a href="https://www.chromium.org/chromium-os/">ChromiumOS</a>, <a href="https://cygwin.com">Cygwin</a>, <a href="https://mariadb.org">MariaDB</a>, -<a href="https://en.wikipedia.org/wiki/MINIX">MINIX</a>, <a href="https://musl.libc.org">musl libc</a>, <a href="https://www.mysql.com">MySQL</a>, <a href="https://en.wikipedia.org/wiki/WebOS"><abbr @@ -175,12 +174,15 @@ ustar interchange format</a>, compressed as described above; older releases use a nearly compatible format. Since version 2016h, each release has contained a text file named “<code>version</code>” whose first (and currently only) line is the version. -Older releases are <a href="https://ftp.iana.org/tz/releases/">archived</a>, -and are also available in an -<a href="ftp://ftp.iana.org/tz/releases/"><abbr -title="File Transfer Protocol">FTP</abbr> directory</a> via a -less secure protocol.</p> -<p>Alternatively, a development repository of code and data can be +<a href="https://ftp.iana.org/tz/releases/">Older archived releases are +available</a> via +<a href="https://en.wikipedia.org/wiki/HTTPS"><abbr +title="Hypertext Transfer Protocol Secure">HTTPS</abbr></a>, +<a href="https://en.wikipedia.org/wiki/Rsync"><abbr +title="remote sync">rsync</abbr></a>, and +<a href="https://en.wikipedia.org/wiki/FTP"><abbr +title="File Transfer Protocol">FTP</abbr></a>. +<p>Alternatively, a development repository of code and data can bem retrieved from <a href="https://github.com">GitHub</a> via the shell command:</p> <pre><code><a href="https://git-scm.com">git</a> clone <a href="https://github.com/eggert/tz">https://github.com/eggert/tz</a> @@ -195,7 +197,7 @@ After obtaining the code and data files, see the The code lets you compile the <code><abbr>tz</abbr></code> source files into machine-readable binary files, one for each location. The binary files are in a special format specified by -<a href="https://www.rfc-editor.org/rfc/9636">The +<a href="https://www.rfc-editor.org/rfc/rfc9636">The Time Zone Information Format (<abbr>TZif</abbr>)</a> (Internet <abbr title="Request For Comments">RFC</abbr> 9636). The code also lets @@ -249,7 +251,7 @@ with lines terminated by <a href="https://en.wikipedia.org/wiki/Newline"><abbr title="linefeed">LF</abbr></a>, which can be modified by common text editors such as <a href="https://www.gnu.org/software/emacs/">GNU Emacs</a>, -<a href="https://gedit-technology.github.io/apps/gedit/">gedit</a>, and +<a href="https://gedit-text-editor.org">gedit</a>, and <a href="https://www.vim.org">vim</a>. Specialized source-file editing can be done via the <a href="https://packagecontrol.io/packages/zoneinfo">Sublime @@ -377,21 +379,16 @@ calculates the current time difference between locations.</li> <section> <h2 id="protocols">Network protocols for <code><abbr>tz</abbr></code> data</h2> <ul> -<li>The <a href="https://www.ietf.org">Internet Engineering Task Force</a>’s -<a href="https://datatracker.ietf.org/wg/tzdist/charter/">Time Zone Data -Distribution Service (tzdist) working group</a> defined <a -href="https://www.rfc-editor.org/rfc/rfc7808">TZDIST</a> -(Internet <abbr>RFC</abbr> 7808), a time zone data distribution service, -along with <a href="https://www.rfc-editor.org/rfc/rfc7809">CalDAV</a> +<li><a href="https://www.rfc-editor.org/rfc/rfc7808">Time Zone +Data Distribution Service</a> (TZDIST, Internet <abbr>RFC</abbr> 7808) +is associated with +<a href="https://www.rfc-editor.org/rfc/rfc7809">CalDAV</a> (Internet <abbr>RFC</abbr> 7809), a calendar access protocol for transferring time zone data by reference. <a href="https://devguide.calconnect.org/Time-Zones/TZDS/">TZDIST -implementations</a> are available. -The <a href="https://www.ietf.org/mailman/listinfo/tzdist-bis">tzdist-bis -mailing list</a> discusses possible extensions.</li> -<li>The <a href="https://www.rfc-editor.org/rfc/rfc5545"> -Internet Calendaring and Scheduling Core Object Specification -(iCalendar)</a> (Internet <abbr>RFC</abbr> 5445) +implementations</a> are available.</li> +<li>The <a href="https://www.rfc-editor.org/rfc/rfc5545">iCalendar format</a> +(Internet <abbr>RFC</abbr> 5445) covers time zone data; see its VTIMEZONE calendar component. The iCalendar format requires specialized parsers and generators; a @@ -423,10 +420,6 @@ available under the <a href="https://www.gnu.org/copyleft/gpl.html"><abbr>GNU</abbr> General Public License (<abbr title="General Public License">GPL</abbr>)</a>.</li> -<li><a href="https://sourceforge.net/projects/tzical/">tziCal – tz -database conversion utility</a> is like Vzic, except for the <a -href="https://dotnet.microsoft.com">.NET framework</a> -and with a <abbr>BSD</abbr>-style license.</li> <li><a href="https://metacpan.org/release/DateTime-TimeZone">DateTime::TimeZone</a> contains a script <code>parse_olson</code> that compiles @@ -616,6 +609,9 @@ the Apache License.</li> library that translates between <abbr>UT</abbr> and civil time and can read <abbr>TZif</abbr> files. It is freely available under the Apache License.</li> +<li>The <a href="https://golang.org">Go programming language</a> +has a <abbr>TZif</abbr> file reader <a +href="https://pkg.go.dev/time#LoadLocationFromTZData"><code>LoadLocationFromTZData</code></a>.</li> <li>The <a href="https://github.com/nayarsystems/posix_tz_db"><code>posix_tz_db</code> package</a> contains Python code @@ -678,10 +674,6 @@ href="https://www.mozilla.org/en-US/thunderbird/">Thunderbird</a>. It displays multiple clocks in the application window, and has a mapping interface to <a href="https://www.google.com/earth/">Google Earth</a>. It is freely available under the <abbr>GPL</abbr>.</li> -<li><a href="https://golang.org">Go programming language</a> -implementations contain a copy of a 32-bit subset of a recent -<code><abbr>tz</abbr></code> database in a -Go-specific format.</li> <li>Microsoft Windows 8.1 and later has <code><abbr>tz</abbr></code> data and <abbr>CLDR</abbr> data (mentioned <a href="#CLDR">below</a>) used by the @@ -836,7 +828,8 @@ Saving Time – History, rationale, laws & dates</a> and summarized in History of Daylight Saving Time</a>.</li> <li><a href="https://www.laphamsquarterly.org/roundtable/time-lords">Time Lords</a> discusses how authoritarians manipulate civil time.</li> -<li><a href="https://www.w3.org/TR/timezone/">Working with Time Zones</a> +<li><a href="https://www.w3.org/TR/timezone/">Working with Time +and Time Zones</a> contains guidelines and best practices for software applications that deal with civil time.</li> <li><a href="https://webspace.science.uu.nl/~gent0113/idl/idl.htm">A History of @@ -851,10 +844,7 @@ Zone Concepts</a> discusses terminological issues behind time zones.</li> <h2 id="national">National histories of legal time</h2> <dl> <dt>Australia</dt> -<dd>The Parliamentary Library commissioned a <a -href="https://parlinfo.aph.gov.au/parlInfo/download/library/prspub/359V6/upload_b…">research -paper on daylight saving time in Australia</a>. -The Bureau of Meteorology publishes a list of <a +<dd>The Bureau of Meteorology publishes a list of <a href="http://www.bom.gov.au/climate/averages/tables/dst_times.shtml">Implementation Dates of Daylight Savings Time within Australia</a>.</dd> <dt>Belgium</dt> @@ -915,8 +905,8 @@ covers the history of local time in the Netherlands from ancient times.</dd> href="https://www.dia.govt.nz/Daylight-Saving-History">History of Daylight Saving</a>.</dd> <dt>Palestine</dt> -<dd>The Ministry of Telecom and IT publishes a <a -href="https://mtit.pna.ps/home/TimeZone" +<dd>The Ministry of Telecom and Digital Economy publishes a <a +href="https://mtde.gov.ps/home/TimeZone" hreflang="ar">history of clock changes (in Arabic)</a>.</dd> <dt>Portugal</dt> <dd>The Lisbon Astronomical Observatory publishes a @@ -957,9 +947,6 @@ zone shifts, and many scientific studies have been conducted. This section summarizes reviews and position statements based on scientific literature in the area.</p> <ul> -<li>In 2022 the American Medical Association issued a -<a href="https://www.ama-assn.org/press-center/press-releases/ama-calls-permanent-st…">statement -supporting permanent standard time</a> on health grounds.</li> <li>Carey RN, Sarma KM. <a href="https://bmjopen.bmj.com/content/7/6/e014319.long">Impact of daylight saving time on road traffic collision risk: a systematic @@ -969,22 +956,12 @@ This reviews research literature and concludes that the evidence neither supports nor refutes road safety benefits from shifts in time zones.</li> <li>Havranek T, Herman D, Irsova D. -<a href="https://www.iaee.org/en/publications/ejarticle.aspx?id=3051">Does -daylight saving save electricity? A meta-analysis</a>. +Does daylight saving save electricity? A meta-analysis. <em>Energy J.</em> 2018;39(2):35–61. doi:<a href="https://doi.org/10.5547/01956574.39.2.thav">10.5547/01956574.39.2.thav</a>. This analyzes research literature and concludes, “Electricity savings are larger for countries farther away from the equator, while subtropical regions consume more electricity because of <abbr>DST</abbr>.”</li> -<li>Malow BA. <a -href="https://academic.oup.com/sleep/article/45/12/zsac236/6717940">It is time -to abolish the clock change and adopt permanent -standard time in the United States: -a Sleep Research Society position statement</a>. -<em>Sleep.</em> 2022;45(12):zsac236. -doi:<a href="https://doi.org/10.1093/sleep/zsac236">10.1093/sleep/zsac236</a>. -After reviewing the scientific literature, the Sleep Research Society -advocates permanent standard time due to its health benefits. <li>Neumann P, von Blanckenburg K. <a href="https://journals.sagepub.com/doi/full/10.1177/0961463X241310562">What time will it be? A comprehensive literature review on daylight saving time</a>. @@ -993,6 +970,30 @@ doi:<a href="https://doi.org/10.1177/0961463X241310562">10.1177/0961463X24131056 This reviews DST’s effects on electricity, health, crime, road safety, and the economy, focusing on research since 2010, and concludes that year-round standard time is preferable overall. +</ul> + +<p>The following medical societies have taken positions on the +advisability of clock shifts:</p> + +<ul> +<li>In 2022 the American Medical Association issued a +<a href="https://www.ama-assn.org/press-center/press-releases/ama-calls-permanent-st…">statement +supporting permanent standard time</a> on health grounds.</li> +<li>Crawford MR, Winnebeck EC, von Schantz M <em>et al</em>. +<a href="https://onlinelibrary.wiley.com/doi/10.1111/jsr.14352">The +British Sleep Society position statement on Daylight Saving Time in the UK</a>. +<em>J Sleep Res.</em> 2025;34(3):e14352. +doi:<a href="https://doi.org/10.1111/jsr.14352">10.1111/jsr.14352</a>. +This recommends that the UK abolish DST for health reasons.</li> +<li>Malow BA. <a +href="https://academic.oup.com/sleep/article/45/12/zsac236/6717940">It is time +to abolish the clock change and adopt permanent +standard time in the United States: +a Sleep Research Society position statement</a>. +<em>Sleep.</em> 2022;45(12):zsac236. +doi:<a href="https://doi.org/10.1093/sleep/zsac236">10.1093/sleep/zsac236</a>. +After reviewing the scientific literature, the Sleep Research Society +advocates permanent standard time due to its health benefits.</li> <li>Rishi MA, Cheng JY, Strang AR <em>et al</em>. <a href="https://jcsm.aasm.org/doi/10.5664/jcsm.10898">Permanent standard time is the optimal choice for health and safety: @@ -1144,12 +1145,16 @@ to discontinue the use of leap seconds by 2035, and requested that no discontinuous adjustments be made to UTC for at least a century. The World Radiocommunication Conference <a href="https://www.itu.int/dms_pub/itu-r/opb/act/R-ACT-WRC.15-2023-PDF-E.pdf">resolved -in 2023</a> to cooperate with this process. -<a href="https://www.preprints.org/manuscript/202406.0043/v1">A proposal -to change the leap-second adjustments to Coordinated Universal Time</a> -(doi:<a href="https://doi.org/10.1088/1681-7575/ad6266">10.1088/1681-7575/ad6266</a>) -would replace leap seconds with 13-second leap smears occurring once per +in 2023</a> to cooperate with this process. One proposal to implement this +would replace leap seconds with seven 13-second leap smears occurring once per decade until 2100, with leap smears after that gradually increasing in size. +See: +<ul> +<li>Levine J. <a href="https://www.preprints.org/manuscript/202406.0043/v1">A +proposal to change the leap-second adjustments to +coordinated universal time</a>. <em>Metrologia.</em> 2024;61(5):055002. doi:<a +href="https://doi.org/10.1088/1681-7575/ad6266">10.1088/1681-7575/ad6266</a>.</li> +</ul> However, there is still no consensus on whether this is the best way to replace leap seconds. </li> -- 2.48.1

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Using curved quotes etc. in TZDB HTML
by Paul Eggert Aug. 30, 2025

Aug. 30, 2025

After looking at today’s little change[1] to one of TZDB’s HTML files, I noticed that it cited Morrison et al’s 2020 paper but changed the paper’s title to use straight quotes 'like this' instead of curved quotes ‘like this’. Although TZDB’s HTML files mostly use straight quotes, they’re not methodical about it, and anyway straight quotes are to some extent a relic of the 20th century and in HTML files we can now reliably use curved quotes. So I composed a patch (attached) to be more consistent about quoting, and to use curved quotes except in places where the quotes are part of computer code and need to be straight. I haven’t installed this patch, though, because it’s annoying to edit HTML that looks like this: strings like “Prague”, “Praha”, “Прага”, and “布拉格”. I’d rather edit HTML that looks like this: strings like “Prague”, “Praha”, “Прага”, and “布拉格”. Since the HTML files are already UTF-8 encoded (otherwise they wouldn’t contain those non-ASCII letters) this shouldn’t be a problem with today’s editors. In 2014[2] I held off on making such a change because Garrett Wollman wrote that XEmacs 21.4 does not support quotes ‘like this’ or “like this”. However, XEmacs 21.4 has not been updated since 2009 and by now I would think XEmacs users would be using either XEmacs 21.5 (even though it’s still “beta”) or GNU Emacs, and both of these do support curved quotes. So instead of installing this patch, I’m inclined to install a different one in which HTML files use UTF-8 quotes “like this” rather than harder-to-read HTML entities “like this”. If this is OK we can also do something similar with other special characters such as “–” instead of “–”. Comments welcome. I am ccing this email to Garrett to see whether XEmacs 21.4 is still an issue with him. [1]: https://lists.iana.org/hyperkitty/list/tz@iana.org/message/BH63ZL5DHEBJPT2C… [2]: https://mm.icann.org/pipermail/tz/2014-June/046053.html

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Re: Disabling adjustment, hyphenation, SGR, and page headers and footers in man pages
by Paul Eggert Aug. 28, 2025

Aug. 28, 2025

On 2025-08-27 16:42, G. Branden Robinson wrote: > I sent this to tz(a)iana.org a few days ago, but it appears to have gotten > discarded, maybe because I am not subscribed to the list. Yes, it's August and I suspect mailing list reviewers are on vacation. For tz list readers: Branden's original email is archived here: https://lists.gnu.org/r/groff/2025-08/msg00041.html > I have a suggestion for accomplishing all of the tasks named in the > Subject with command-line options to (recent) nroff. If I understand > the "workman.sh" script correctly, all that would be left for your > pipeline is to strip a trailing blank line. Thanks for the suggestion. As TZDB has been shipping *.txt files with single header and trailer lines for some time, I think we can simply prefer that style now for groff; this removes the need to strip a trailing blank line. For traditional nroff the best we can easily do is omit all headers and trailers, to avoid irritating headers elsewhere. > You might find it more convenient to use command-line options than to > append to macro definitions and otherwise inject *roff into nroff's > input stream (which is interpreted only after the macro package is > loaded, a fact that will have important consequences in groff 1.24). Thanks for the suggestion. Although this assumes groff we can do it just for groff (and for mandoc) and continue to do things the traditional way on old-fashioned (by now, very old-fashioned) hosts. I installed the attached proposed patches to implement your suggestion and a bit more.

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Re: question regarding Mongolian timezone /Hovd GMT+/
by Munkh-Erdene Erdenebat Aug. 27, 2025

Aug. 27, 2025

Dear IANA Colleagues, I hope this message finds you well. My name is Munkh-Erdene from Mobicom Corporation, a mobile phone operator in Mongolia. I have a question regarding the Mongolian timezone, specifically for the Hovd region. According to various online sources, Mongolia currently has two time zones: Hovd (UTC+7) and Ulaanbaatar (UTC+8). The Hovd timezone is observed in three provinces: Hovd, Bayan-Ulgii, and Uvs. However, when I checked the tzdata files (zone.tab and zone1970.tab), it lists five provinces under the Hovd timezone. My understanding is that it should be only the three provinces mentioned above. Could you please advise on the process for requesting a correction in tzdata? Are there any specific requirements we need to meet? Also, please let me know if my understanding of the timezone coverage is incorrect. Thank you for your time and support. MUNKH-ERDENE Erdenebat Manager Core Network Department /CND/ CN&BSD/TS [mobicomnewlogo] Peace Avenue 3/1, Post Office-46 Ulaanbaatar-14201, Mongolia. Mobile : (976) 94081000 Web : www.mobicom.mn<http://www.newcom.mn/> From: Munkh-Erdene Erdenebat Sent: Wednesday, March 13, 2024 5:28 PM To: tz-owner(a)iana.org<mailto:tz-owner@iana.org> Subject: question regarding Mongolian timezone /Hovd GMT+/ Dear IANA Colleagues, How are you, doing well. I am Munkh-Erdene from Mobicom Corporation, which is Mongolian mobile phone operator. I've question regarding Mongolian timezone. We have some misunderstanding regarding Mongolian timezone, specially for Hovd region. As we checked from internet, it says there is 2 timezone in Mongolia now. Hovd+7 and Ulaanbaatar +8. Behind of Hovd region, there is 3 provinces which is Hovd, Bayan-Ulgii & Uvs. [cid:image004.png@01DC1810.84CC7F10][cid:image007.jpg@01DC1810.84CC7F10] World Time Zone Map (24timezones.com)<https://24timezones.com/timezone-map> Mongolia Time Zone - WhichTimezone<https://whichtimezone.com/asia/mongolia/> But when I checked from tzdata file. Zone.tab & zone1970.tab files. There is 5 aimags behind of Hovd region, it should be 3 provinces which is Hovd, Bayan-Ulgii & Uvs. We want to correct it on tzdata, how can we send request to you and is there any requirements from you? please correct me if I was checked wrongly. [cid:image008.jpg@01DC1810.84CC7F10] [cid:image009.jpg@01DC1810.84CC7F10] MUNKH-ERDENE Erdenebat Department Manager Network Operation & Maintenance Department /NOMD/ TOMD/TOMS [mobicomnewlogo] Peace Avenue 3/1, Post Office-46 Ulaanbaatar-14201, Mongolia. Mobile : (976) 94081000 Web : www.mobicom.mn<http://www.newcom.mn/> ???????? ?????? ????? ?????? ?? (????????????? ????) ?????? ?????? ?????????? ?????????, ?????? ???? ??? ????? ???????? ???????????? ?????. ?? ????? ??????? ??????????? ???????? ?? ??????? ?????????????, ????????? ???????? ?????? ?????? ??????????? ???????????? ???? ?????????? ? ??????? ????????????? ??? ?? ????????????? ??. ????? ?? ?? ????? ??????? ??????? ???????? ?????? ????? ??? ??? ?????? ????? ??????? ????????? ????? ????? ?????? ?????? ?????? ????????, ?????????? ????? ????? ????? ??????? ?????? ????????? ??? ????? ?????? ???? ??????? ???? ??. ???????? ?????? ???????? ??????????? ?????????? ?????? ????????? ?????????, ??????????, ?????? ?????? ????? ?? ??????????? ????????? ??????? ????? ?????? ????, ?? ?????? ????? ????? ??? ?????? ???????? ??. Disclaimer This email (including any attachments) is intended only to be read and used by the addressee. It may contain confidential or legally privileged information, which is not waived if it is mistakenly delivered to you. If you are not the intended recipient, please immediately notify the sender by return email and delete both messages from your system; any disclosure, copying, distribution, or any action taken or omitted to be taken in reliance on it, is prohibited and may be unlawful.

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