So I used the GOG Downloader yesterday to get some installers I hadn't gotten yet, and they came with generic folder names, like gm31 and so on. The Star Wars Tie Fighter/XWing games definitely had this, and I noticed some games had extras missing names (I don't have which on hand) when I was going through -- just names like "p398520".

Here's one: Wing Commander 3 Heart of the Tiger has a bonus titled: "product_bonus_39983"

Tex Murphy: Under a Killing Moon updated today and here's another one:

Under bonus content,
product_bonus_39683
product_bonus_39693
Nice way to indicate what they are (for reference, they appear to be a novel?)

Bugs in the packaging, report to support.