In a recent E-mail, my contact suggested that I contact someone who is the “Head Office Manager”.
The issue: Head office is likely to have many managers. Which one? From context, it was the Head Office Office Manager, that is, the office manager at the head office. Many people do not like having the same word twice in a row even when they each serve a useful purpose.
Another example is “had had”. When I was growing up, I several times saw books where someone had crossed out one of the “had”s in the sequence “had had”. “had” is in the imperfect tense; “had had” is in the pluperfect tense. They do mean different things.