For all you serious Google AdWords advertisers, I spotted an advanced question in the Google AdWords Help forum I don't think I've seen mentioned before our the maximum number of labels you can use in your account.
The question was from Andreas asking about the maximum number of labels that can be used within AdWords accounts. It doesn't seem the help documents have this answer, so Google's Kathleen from the AdWords team dug up the answer.
- The maximum limit of labels per account, is 200 labels per account.
- The maximum number of accounts a single label can be applied to is 1000.
What are AdWords labels? Google has a help document on that, in short, AdWords labels is an additional way to group and report on your AdWords campaigns.
Forum discussion at Google AdWords Help.