What are these super-long file names?

realtime99

I've been having trouble on my computer with file names that are over 255 characters, and in troubleshooting the problem, I discovered some Zotero folders with extremely long filenames without extensions, such as:

storage\urtu3tk6\ebflhryne3t7si0ldxfrddw2h6z_3k4l7iif3pe8vflorxzzyniz3o2im8xfaegpaaj29wn66wkeqzuhkpq3cvgsftn9ajh_cg8hmacpz-

What are these?

adamsmith

parts of webpage snapshots - though normally Zotero shouldn't allow them to be >255 characters.