As a book author, I need to annotate pdf files and share them with others. "Annotate" means Sticky Notes, highlighting text, strikethroughs, etc. My publisher uses Acrobat 9.0, and they are worried that if I use X these annotations may not be compatible with 9. My editor wrote me,
"My concern may not be with the version of pdf, but with the
mark-up/commenting that is added when we mark changes - with [previous edition], the
comp claimed they kept missing corrections on PDF page proofs because they
had a different version of Acrobat and couldn't see them. The interface for
Acrobat X is different and I don't know if it has new or modified mark-up
tools, but my concern is that you mark something in Acrobat X and those of
us with Acrobat 9 can't see what you marked."
Is this really possible, or are X and 9 completely compatible in this regard? Is this simply a question of 9 and X both using PDF 1.7? Are these annotations part of the 1.7 spec, or are they some kind of add-on? Is there an official Adobe document about this that I could point my editor to?
Non-rich-media annotations created in Acrobat X will display perfectly in Acrobat/Reader 9 as there have been no changes to the ISO 32000 implementation for markup and comment annotations between those versions. They will be fine as far back as Acrobat/Reader 8 with the sole exception of HTML anchor tags within rich-formatted comment text (that feature arrived with Acrobat 9.1 via the PDF/1.7-EL5 extension).
Most of the commonly-used markup and comment types will work back as far as Acrobat 6, and some (e.g. sticky notes) back to Acrobat 4, but the PDF would need to be saved as a legacy version to be opened in something that old.