This is the second-most asked question. It's one of the most common questions we get.
On save, Arbortext Editor adds processing instructions, like <?Pub Caret?>. How do I remove processing instructions (PIs) ?
Turning off the PIs is easy. You change an advanced setting in the preferences:
Open Tools->Preferences, and then click the Advanced button. Scroll down until you see "writepi".
This is also documented in help topic #1587.
If you turn off the PIs, you turn them all off. No touchup, no Arbortext extensions, etc. Make sure you really want them off before you turn them all off.
Generally speaking, processing instructions in XML source files aren't problematic. This one, the <?Pub Caret?>, simply stores the last place your cursor was when you saved the file so Arbortext knows where the cursor was last.
Processing instructions are commonly used (by many XML editors and publishing tools) to add additional information used by those tool to do things that step outside the basic XML or doctype specification. Antenna House has some you can insert to trigger specific formatting options. Think of PIs as the escape hatch for tools. Most compliant tools ignore them, especially those that aren't constructed to mach a PI they know to look for (their pis). Generally they're innocuous, but you can change this setting in Arbortext to make sure that they are all stripped out of the source file - no matter what tool put them in.
It can be deleted and shouldn't affect anything downstream. PIs are a standard XML construct that are dismissed by parsers unless they know to look for them--a specific one.