You can put any other conditions, restrictions, and services related to your dwelling. 

In your lease revision, if you see the sentence "There is an annex that is an integral part of this lease and forms an indivisible whole with it", it is simply that there is an annex attached to your lease. 

What is considered an annex: adding an annex in the Annex section; another annex in the Supplemental Document section; or if you have added an endorser in Section H (which is also part of the annex).