I sent a driving licence and redacted the licence number, then overtyped the whole thing with the text in my previous post.

My goal was to make certain that if it leaked, the overtyped expiry date should make it useless after a certain point, and the company name should make any company other than that one question the source.

As a side effect, it'd also clearly identify the source of any leaks - but that wasn't my primary goal.

I moved the text so the name and address (which they already had) and date of birth (which isn't really a secret) were clearly readable.

>My goal was to make certain that if it leaked, the overtyped expiry date should make it useless after a certain point, and the company name should make any company other than that one question the source.

>As a side effect, it'd also clearly identify the source of any leaks - but that wasn't my primary goal.

Wouldn't a malicious actor just add block text over your text saying "only for identity verification for SomeOtherCompany" ?

They could do the same for the expiration date, although I wonder if any company actually bothers to check the expiration date

I don't know how GP did it, but I would have made the text translucent and make sure it covered the entire image so that there's no easy way to obfuscated the watermark without also obfuscating the license itself.

Ahh, of course - I didn't think of that. Thanks, obvious now that you mention it :-)

translucent text is nearly trivial to remove