Read the following context and answer the question.
Context: I need the new gate code , and alarm deactivating procedure , as I forget . It 's been a long while since I ' ve keyed in , and I have n't yet at the new building . I wrote to my landlady , because she all of this insurance stuff that takes care of things like this , and I did n't want to pay a big plumbing bill , or have her fight with me for not doing it her way .
Question: What reason or use is a " Gate code " ?
Answer:


Opens the main entry to the residence .