Allowed to be put into legal document, or taken out (7)
I believe the answer is:
deleted
'taken out' is the definition.
(deleting is a kind of taking out)
'allowed to be put into legal document' is the wordplay.
'allowed to' becomes 'let' (to let something happen is to allow it).
'be put into' indicates putting letters inside.
'legal document' becomes 'deed' (deed is a kind of legal document).
'let' put into 'deed' is 'DELETED'.
'or' is the link.
(Other definitions for deleted that I've seen before include "Effaced" , "Expunged" , "Removed" , "Struck out" , "Erased" .)