Searching doesn't seem to work as expected

Searches for some text in pdfs doesn’t seem to work.

I can find a bunch on invoices from my phone company using ‘bt.com’ (which appears on every pdf invoice), but when I search for the account code (which also appears on every invoice) and has the form ‘GB 256 512’ nothing is returned from the search.

A Spotlight searchfor the account number finds all the invoices

Does the search not work for numbers?

What am I missing?

I don’t have your documents, of course, but if I dummy up some PDFs that contain those strings, I am able to find them in DEVONthink with no problems – and with greater accuracy than Spotlight, where I get several false positives.

There is no reason this should never work, but there are settings that could make it sometimes not work.

How are you searching? In the Tools > Search panel, or in the Edit > Find > In Database… tool, or in the command-F [Find] tool for the selected document(s)? What are your parameters in the search tool you are using – e.g., settings such as “Search for All”, “Search for Content”, and so on? Are you quoting the search string?