The search is an exhaustive case-insensitive sub-string search. This means that a
'perl' will find
It will find a phrase even if the phrase wraps around onto multiple lines.
If the results indicate your query is present on a page, go to that page and use the "Find on this page" feature of your browser to locate it (Ctrl-F on Windows browsers).
If this does not find the query, it may mean that your term or phrase is not part of the visible HTML document. Rest assured though, that the word or phrase is in that file, possibly as a comment or as part of a META tag. You may have to use the 'View Source' feature of your browser in this case.
Note also that the search term may appear more than once on a page, so don't stop at the first one found.
The search feature will be tweaked and honed so be sure to check it regularly.