The left-to-right mark character is an invisible control character. If you open up a text file in VIM containing such a character, you will see it as
<200e> in Unicode.
If you want to get rid of all occurrences of this control character, you can do:
<ctrl>+<shift>+u to enable entering the character by Unicode code points, followed by the actual character code and
<enter> key. It will loke like this:
However, not all terminals are supported.