I have found a strange behaviour when dealing with tags.
When you look at a forum message, there is the list of tags associated with it (if any); clicking on the "view all" link shows a page with the tags list and an options dropdown menu.
It seems that the menu is emty when the tags were set by other users, while it shows 2 options if tags have been set by me.
I wasn't able to locate a message with both tags from me and from others to see what happens.
This is what I see (Chrome 54.0.2840.99 m on Win10 Pro):
Note: image actually refers to an example of mine in the LabWindows/CVI user group but the behaviour is the same for regular forum boards