Do you know how to delete this character 0xFEFF (ZERO WIDTH NO-BREAK SPACE) between two letters. When I copy-past it in find-change dialog box, it appears like an index tag (~I in GREP). But when I search it, only index tags are find.
If you don't need these characters in your text you can delet them with find-change.
change: leave empty
That's not a GREP Find/Change pattern, it's a TEXT Find Change expression.
also note that this special character is used for several applications.
So be careful what instants you want to remove.
( ACP )
But I wan't te delete only space, not index tag.
I think it is impossible.
FEFF is a special code, just in case you did not know.
Because it has no effect, it is used for a special meaning. It is included at the start of many, perhaps most Unicode files. Apps can see that a file starts with hex FFFE (UCS2-BE) or FEFF (UCS2-LE) or EFBBBF (UTF-8) - all of which are U+FEFF - and know it is Unicode instead of plain text. You may often find it in your text, and it's probably best to ignore it.
"But I wan't te delete only space, not index tag"
FEFF is 0 width space
your screenshot is clearly showing an FEFF special character between the R and the A.
You could try to shield all index markers from your search if you first apply a character formatting to all index tags that is unique to your text. Perhaps a character width of 50%. Then in a second search you are looking for a character with pattern <FEFF> plus a character width of 100%.
TEXT Find pattern for index markers:
( ACP )
Great idea. You are resolved the problem.
A tip to keep in mind.
But also note that <FEFF> special characters are also used for other purposes.
InDesign Note objects for example. Or hyperlink anchor markers:
( ACP )
Thanks for this presentation of the character.