MS Word and Excel picks up the first line of text or at least the first few words as the default file name when saving a new document. This is a handy feature.
save a new document
I had to fill in the name if I didn't want it called untitled1
User Profile Reset: No
use the first line of text as the file name unless I change it
User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:57.0) Gecko/20100101 Firefox/57.0
*** This bug has been marked as a duplicate of bug 58685 ***