The keywords are case-insensitive.

The search result contains the hits that match any of the given keywords.

If the result shall contain only these pages that match all keywords, then you should add a plus character in front of all keywords.
Example:
"+guidelines +internet" will match all pages, that contain both keywords.

If the result contains too many matches, then you can exclude keywords with a hyphen in front of the keyword.
Example:
"guidelines -internet" will match all pages, that contain the word "guidelines" but not "internet".

The search engine only supports exact pattern matching. If you enter "guideline", then the search engine will not find a word like "guidelines".

The search engine does not support phrases.