What is #@(#) in Kornshell syntax

I'm looking at a script on an AIX box where several lines begin with #@(#)

What does that indicate? Clearly doing a Google search is totally fruitless for symbols.

Here are the lines from the script:

#!/usr/bin/ksh
#
#@(#)
#@(#) USAGE: dump_master_db [opts] SERVER [AREA]
#@(#)  opts: -p PAGENAME : send Pages to PAGENAME rather than the default (usually database)
#@(#)        -nodbcc     : will not do the DBCCs before the dump
#@(#)                     -c COMPRESSION_LEVEL : dump the database at the stated compression level.
#@(#)
#@(#) This script will do some DBCCs, truncates the log and then dumps the master database on any SERVER
#@(#) The SERVER parm is used to build the logical device name as follows:
#@(#)     SERVER_master_dump
#@(#) NOTE: There is no AREA and no stripes for this dump device.
#@(#)       COMPRESSION: VALUES 1 (least) to 9 (most compressed).
#@(#)       Currently, we only use values of none  to 1.