Each tag gets a stable code (01-99) assigned by the server and stored in tags.json; existing tags get one when the file is loaded. A fixed-width Filters column shows the codes of the active tags found in each message (room for 3, then 2 + "+N", all listed in the tooltip). Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>