Errors in PDF column

The PDF column has numerous errors. I am not sure how best to fix them and since I have serious doubts about the value of this article I'm not going to try right now. Here goes:

"Langage Type: Subset of PostScript page description programming language". This is false. The PDF language has roots in PostScript but it is not at all a subset. If it were, then you would be able to execute all PDF files in a PostScript interpreter.
"Full file content compression: Compression at page level only". First I have no idea why "full file" vs "page level" is even interesting: what is interesting is how the file sizes compare for comparable content. But in any case it is not true to say PDF only has "compression at page level." All the non-stream objects in the whole file can be put into a stream and compressed as a unit.
"Multiple documents in one file: No". False. Multiple documents can be placed in the PDF file using the file attachment mechanism.
"Alpha channel in color definitions: no". Misleading at best. PDF supports full vector transparency. Syntactically it's expressed by putting alpha in the graphics state rather than the setcolor operator but that is functionally equivalent.
"Change Tracking: No". Debatable, depending on what you mean by change tracking. If a PDF is modified entirely via incremental updates, the entire history of the file can be recovered programmatically. In practice, I believe this is rarely done.