Disables parsing of the archive_name field on the command line. This switch must be used with the -ai (Include archives) switch. If you use a file list for your archives, you specify it with the -ai switch, so you need to disable parsing of archive_name field from command line.
7z t -an -ai!*.7z -ax!a*.7z
tests all *.7z archives, except a*.7z archives.