mystery symbols

Since my email to the support was not replied to I am posting here…

I would like to know what these (pivot?) symbols mean:

I don’t know how to look them up in the user guide because they are images, not text…

Also, the problem with IK detailed in the General Discussion forum under ‘strange bone makeup’ persists.

Thanks for any help!

OK, now I know that these symbols appear as endpoints of motion paths.