A method to search questions on more than one criteria (not tag)
40396
Add advanced search options to the help pages
75958
"Search Before Asking": A Four Year Update
61980
Is there a way to perform a search in such a way as to exclude a specific tag?
133565
Allow "or" in searches using tags for Stack Overflow and other Stack Exchange sites?
93056
How to use multiple criteria for -find
26374
How to search a string in the list of answers added by me on Stack Overflow?
115612
Distinguish synonyms from single-tag questions on the /tags page
126132
The Unanswered Section vs. the Unanswered Question Tab: A Critique
86240
Please add the ability to filter [Closed] questions out of my results
82039
Search for singleton tags on questions
72253
Excluding tags from search results
104079
Searching for posts without a tag borks the search parameters
143725
How to search multiple sites at once?
77231
Span Stack Exchange sites for tags, searches, and related questions
21238
Is there a way to search all sites at once?
119108
Select on multiple criteria with XPath
4953
Search [tag1] OR [tag2]