accession

a process of increasing by addition (as to a collection or group); "the art collection grew through accession"

(civil law) the right to all of that which your property produces whether by growth or improvement

something added to what you already have; "the librarian shelved the new accessions"; "he was a new addition to the staff"

agreeing with or consenting to (often unwillingly); "accession to such demands would set a dangerous precedent"; "assenting to the Congressional determination"

the right to enter

the act of attaining or gaining access to a new office or right or position (especially the throne); "Elizabeth's accession in 1558"

make a record of additions to a collection, such as a library