The annotations vocabulary provides syntax for comment-like annotations that can be looked up with Factor's usage mechanism.
!AUTHOR

!BROKEN

!BUG

!FIXME

!HACK

!LICENSE

!LOL

!NOTE

!REVIEW

!TODO

!XXX

To look up annotations:
AUTHORs. ( -- )

BROKENs. ( -- )

BUGs. ( -- )

FIXMEs. ( -- )

HACKs. ( -- )

LICENSEs. ( -- )

LOLs. ( -- )

NOTEs. ( -- )

REVIEWs. ( -- )

TODOs. ( -- )

XXXs. ( -- )