# the relationship between the tags

If a person is only interested in number theory, then he/she would just want to access only a few tags, such as number theory, elementary number theory, diophantine equation, etc. But if we select both “number-theory” and "elementary-number-theory" tags, then we will get the posts which tag both “number-theory” and "elementary-number-theory" :

663

questions tagged

(number-theory) (elementary-number-theory)

So the relationship between them is "and", I'd like to search the post which tag is "number-theory " or "elementary-number-theory", hence the relationship between them is "or", I wonder if one can do this ?

• Currently the tags are just friends, but rumor has it that [number-theory] is going to change its Facebook to "It's complicated" and [elementary-number-theory] won't.
– Asaf Karagila Mod
Jul 18 '13 at 15:53
• @Asaf Karagila You exactly answered my question in the title! Jul 18 '13 at 15:59
• meta.SO: Search (tag1) OR (tag2) Jul 20 '13 at 14:50
• You can also use filters to view questions from some set of tags. (But MathJax is not rendered in the titles there.) Jul 20 '13 at 14:52
I just tried putting [number-theory] or [elementary-number-theory] in the search box, and it seems to work. I get 8,011 questions tagged (number-theory) or (elementary-number-theory).
• It is possible to exclude a tag from your search by preceding it with -. For example, you can search for [number-theory] -[elementary-number-theory] or the other way around. The xor syntax is not supported, possibly because there is no realistic use case for it. Jul 21 '13 at 0:38