A lot of people were unhappy that the old search defaulted to OR, and I agreed.

With the change of Stack Exchange's search engine it now defaults to AND and everybody is happy.

But actually sometimes I do want to use OR. There's plenty of concepts that can be expressed in different ways or with different vocabulary. In these cases I like to use OR between synonyms:

  • url OR uri schema OR protocol
  • seek OR fseek
  • options OR prefs OR preferences OR settings OR config
  • folder OR dir OR directory
  • parameter OR param OR argument OR arg

I've tried or, OR, and | but none seem to work. Nothing is mentioned under "Advanced Search Tips".

(I'm tagging support in case it's there but I can't find it and feature-request in case it's not there.)

  • 1
    I think the problem with both systems is that it is not obvious how to mark terms optional or required, or how weighting works. I was expecting -term for forbidden and +term for required, but that doesn’t quite seem to work. I think the forbidden may work though. – tchrist Jan 13 '13 at 16:23
  • Otherwise a single argument like ORQUERY (or any other words) would be nice to copy former behavior. – AurelienB Jan 17 '13 at 15:00
  • 1
    @BethWhitezel Not a duplicate; that one's just about tags, while this one is about all search terms. – michaelb958 Mar 22 '14 at 5:52
  • Oh interesting, thanks. – Beth Whitezel Mar 22 '14 at 6:04

I got zero results doing the search [php] or [mysql], and realized that the Advanced Search Tips don't say how to do an 'OR' search (and also I found the Search Page referenced in the FAQ is no longer there).

I found the following situations:

  1. For doing tag only searches you can use [php] [or] [mysql]
  2. For word searches you can use php or mysql
  3. For phrase searches (with quotes on words) I couldn't get either to work, if you use single quotes, then it seems like you actually get an 'and' search

Could we please have a definitive explanation or doing OR searches in SE?

  • shouldn't that mean that "php or FakeWordThatNoOneWillEverWriteInAQuestion" should return all question with php in the text? Just tried it and returned 0 results, so I fear number 2 is wrong. – SPArchaeologist Jan 28 '13 at 14:15
  • @SPArchaeologist, hmmm, looks like I was wrong, have edited. – Lance Roberts Jan 28 '13 at 14:22
  • 1
    BTW, just tried "php [or] FakeWordThatNoOneWillEverWriteInAQuestion" and that doesn't work too – SPArchaeologist Jan 28 '13 at 14:35

According to this comment there isn't a way to do this. Apparently the search engine never handled it.


Another case in which OR doesn't seem to work is the user: operator.

Searching user:1 OR user:2 only finds posts by user 2 and says «results found containing or search options user 2». Apparently the "redundant" operator is just ignored.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .