pdf 'standardisation' has been a hard road, though, as often happens when you try to standardise a 'de-facto standard'. (Remember the 'document wars'?) Most of it is now controlled by an external body but some still by Adobe - e.g. 'Adobe Javascript'. I think this javascript is what causes so many security vulnerablities: you're better off with a reader that doesn't support it for day-to-day use.

History and standardization of Portable Document Format

It doesn't help that organisations that publish pdf files often use Adobe software and produce the default version of pdf that it produces rather than the lowest version that the document needs. That ensures maximum incompatibility with free pdf readers, which used to be a common problem on Linux. That happens less often now - I think the format has stopped evolving so fast.

It also doesn't help when, as happened recently, a building society (US: a sort of bank) publish an application form with white text on a pale blue background. I don't have a colour printer.