CRM has this nice entity browser that is supposed to show you info about your entities, like what fields there are and how long they can be.  You go to your server and add /sdk/list.aspx to the url and it shows you what entitites you have and what their attributes are.

I used to rely on it because as a programmer, it’s the quickest/most convenient way to get the length information and the ‘valid for update’ information about fields.  Unfortunately, it’s apparently unreliable.

The below screenshot is from a client site. They only have 1 CRM organization configured, yes I’m pointing to the right server on both, and yes their contact is published.  But the entity browser does not show that the fields have had their sizes reduced (to better fit on mailing labels), and if I relied on this to write my code for working with addresses, I’d get it all wrong.