Tags Disappear

Why do Tags that I have added disappear? I must be doing something wrong. I make tags of all components then when I save the file it and it asks to purge the unused components I click yes and they disappear. I thought the tags would be safe since the components are used. Here’s the skp file:
F-Clamp, 24_ (1).skp (201.2 KB)

In your model none of the components have tags applied to them. Since all of the components are untagged, the tags you made are unused and would get purged.

I understand from the screensholt that entity information must indicate that the component is tagged. I am missing how to make entity information show that a component is, in fact, tagged.

In Entity Info, click on the drop down arrow at the right end of the Tags window and choose the tag you wish to put on the selected object(s)…

That’s what I was missing. Thank you.