> Since there is no means to ‘verify’ that a PDF file conforms, creators fall back on using Adobe Acrobat, the de facto standard. If Acrobat will open the file then it must be OK! Sadly it turns out that Acrobat is really very tolerant of badly formed PDF files and will always attempt to open them.

I'm grinning widely when reading this.

Until last year I had an opportunity to help maintaining a pdf tools written using Golang. This case where a pdf doc that is not conforming with the standard could be opened in Acrobat but not on other pdf reader tools (including ghostscript) came a lot from our clients and I had to find a way to be able to read/extract the content with a minimum issue because of that.