accession

Something added to what you already have.

“the librarian shelved the new accessions”

Agreeing with or consenting to (often unwillingly).

“accession to such demands would set a dangerous precedent”

The act of attaining or gaining access to a new office or right or position (especially the throne).

“Elizabeth's accession in 1558”

The right to enter.

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.

Make a record of additions to a collection, such as a library.