Implicitly Locked Layers

I just recieved a photoshop document from a graphic designer who had been working on our website. I was happy to recieve the file so I could finish making a few edits but then found that all the layers are implicitly locked. What does this mean? I have been searching all over and cannot find the answer. Does that mean the layers cannot be edited?

Have you checked the layers palette to see if yo ucan unlock them?

found that all the layers are implicitly locked. What does this mean?

How did you come to this conclusion? Are you getting a message? If so, does the message use the words "implicitly locked"?