What is this yellow symbol that can't be deleted and is attached to some type and images

[j4m1eb]

I've inherited a document to work on at it has these little symbols throughout, some attached to nothing, some to text and some to images. I can select them but not delete, right click reveals nothing about then just the optiosn for what they are attached to. 

Google is no help, can't find anything searching on here either.

Anyon know what they are

[BobLevine]

FYI, this is found under Help>About InDesign on Windows.

[Brad @ Roaring Mouse]

"can select them but not delete, right click reveals nothing"

What about double-clicking on them?

[j4m1eb]

Nothing, even when you single click on it you are actaully just clicking through it to whatever it sits on.