The bulk update request #13118 is pending approval.
create implication trapped_in_underwear (268) -> inside_underwear (393)
create implication trapped_in_shoe (401) -> inside_shoe (437)
create implication trapped_in_condom (140) -> inside_condom (21)
create implication trapped_in_foreskin (25) -> inside_foreskin (33)
create implication trapped_in_cage (11) -> caged (538)
Reason: I haven't looked through the posts for each tag, but it seems logical. Would aliases be preferred over implications here? There is precedent for that: trapped_in_bubble is already aliased to in_bubble (topic #34886). Then again, bubbles can't have an exit (otherwise they'd pop!), making the character inherently "trapped", so it could be a special case.
Related:
topic #39551 implication: trapped_in_sock -> inside_sock
topic #47336 alias: inside_bubble -> in_bubble