Problem in Word: mac v. X just cropped up

I have an older Word program, Microsoft Word X for Mac, Service Release 1. It's worked flawlessly for years. A few weeks ago I was playing around to see what different options did, clicked on this and that, and here is what's been happening since.

When I copy a whole Word file page (boilerplate) to an eBay listing I'm making, the copied text is now prefaced with this:

Version:1.0 StartHTML:0000000170 EndHTML:0000002311 StartFragment:0000001709 EndFragment:0000002275
SourceURL:file:///Users/judithmayberry/Desktop/eBay%20Macro.doc

I have to delete it every time from the text before proceeding. Could it be something that eBay has done to text that's copied in? Because it didn't show when I tried to insert it here into this message box! eBay has been making a lot of changes lately, so I wonder if it's their doing.

I looked at all the boxes to check in Preferences and on the Menu bar, but nothing seems related. Can anyone help?

Nope, you're stuck with the metadata that word plunks in there as far as I know.

But it suddenly started appearing after several years of perfect behavior!