Retrieving list of tags used by user starting with some text

To search for hashtags or user names already used following request might be used:

<iq type="set" id="query2">
    <tags xmlns="" like="#test"/>

which will return suggested similar hashtags which where found in database for particular user if following response:

<iq type="result" id="query2">
    <tags xmlns="" like="#test">
        <set xmlns="">
             <first index='0'>0</first>