The Asia/Almaty tzfile generated from recent Github tzdata snapshot contains the following TZ string at the end of the file

$ git describe
2016f-7-ge0a7616
$ strings etc/zoneinfo/Asia/Almaty | tail -1
<+06>-6

This format is not documented in newtzset.3:

       When TZ is used directly as a specification of the time conversion
       information, it must have the following syntax (spaces inserted for
       clarity):

              stdoffset[dst[offset][,rule]]

       Where:

              std and dst    Three or more bytes that are the designation for
                             the standard (std) or summer (dst) time zone.
                             Only std is required; if dst is missing, then
                             summer time does not apply in this locale.
                             Upper- and lowercase letters are explicitly
                             allowed.  Any characters except a leading colon
                             (:), digits, comma (,), ASCII minus (-), ASCII
                             plus (+), and NUL bytes are allowed.