Parents coming to usa 2nd time?

[mrout]

My parents coming to usa second time. Their usa visa is having 5 year Multiple entry. Do they need any document at usa immegration check?

Also my parent has something called "Annotation" mentioned in passport. What does that mean?

[PraetorianXI]

All they need is a defined trip and return back home. It helps if you send them an invitation letter.

It also helps if their previous visit was not too longer (5-6 months) or less than 6 months ago.

Annotation means there's a note on their passport. What does it say? it may be special instructions to be noted by the POE officers.