Description:
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The manual page for `mb_ereg_match` at https://secure.php.net/manual/en/function.mb-ereg-match.php makes no mention that `$pattern` is only matched at the beginning of `$string` (i.e. it includes an implied `^` at the start).

It is mentioned in a user contributed note, but this behaviour really should be included in the main documentation, probably in a highlighted "Note" or "Warning" box, as it is very important for using the function, and the behaviour would be unexpected as most other similar functions in both PHP and other languages do not behave this way.

(It may be a bug in the function and it is not supposed to behave this way, but for compatibility reasons it probably can't be fixed until a major release.)

Test script:
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<?php

// note space at start of $string parameter
echo mb_ereg_match('[[:alpha:]]', ' a') ? 'matched' : 'not matched';


Expected result:
----------------
Based on the documentation as it is, I expected "matched" to be output.

I expect to be able to easily determine what this simple script would output from the documantation.

Actual result:
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"not matched" is output, but the documentation makes no indication that this would be the case.