1. I am wondering if it is possible to add drop-down list with autofill, for example: I choose "ABCD" in drop-down list and Adobe autofill previously choosen fields from date base (for example Excel).
2. How can I highlight (invisible for printers) boxes to fill ?
3. Date box doesn't work in my Adobe :(, when I chose it, it works as normal text box to fill
4. Is it possible to add something from one box? For example I have two boxes to fill: in one box I write: 01.02.2021 and in another box I want to autofill it automatically dd-1.mm.yy+1 so in that case: 31.01.2022
1. Yes, but not from a DB or an Excel file. The data has to be available in plain-text (or PDF) format, and preferably it should be embedded in the PDF file itself, either as a file or hard-coded. Either way, it will require using a custom-made script.
2. There's already a built-in option that does that, called Highlight Form Fields.
3. What application, including exact version number, are you using?
4. Yes, this is possible, but again requires using a script. Try searching the Acrobat forum, as this issue was discussed many times in the past and there are code examples there.