According the the CA Dept of Consumer Affairs website, it's basically anything that would happen with normal use.  

My pal says she's learned that in her state, California, the Dept. of Consumer Affairs Contractors State License Board has a rule that unlicensed workers cannot do more than $500 in work, and that includes cost for parts.

This is addressed on the CA Dept of Consumer Affairs website on security deposits and deductions.  

Don't know the laws in TN but I don't think you can kick anyone out because so and so had an affair with so and so or because so and so left in the middle of the night and only so and so is left behind in your rental.

Just as a reference on the subject, here's a quote from the CA Dept of Consumer Affairs website: If the landlord or the landlord's employees did the work - The itemized statement must describe the work performed, including the time spent and the hourly rate charged.

They always say no.Oh, and when tenants start saying you are required to do something by law - I would tell them that I'd be happy to email them a link to the CA Dept of Consumer Affairs website that explains what a landlord is responsible for and what a tenant is responsible for.  

You also should check your state's Department of Consumer Affairs under tenant-landlord law, rights, etc, which explains those laws in plain English.

The CA Dept of Consumer Affairs has a great website on this issue.  

Also consult California's Department of Consumer Affairs to get a better handle on your rights as a landlord.

Reference NJAC 14:3-3A.6 from the NJ Dept of Consumer Affairs.