There are four general rules that apply to all Google web searches. However, with some tricks, some of the rules can be overwritten.
Google will not suggest vulgar words or phrases
Google's keyword suggestion and auto-complete feature does not allow vulgar words. Example of vulgar words: "sh*t", "f*ck", and "b*tch".
Google ignores case sensitivity
Google queries are not case-sensitive, with the exception of the OR and AND operators. This means that searching for date, DATE, Date, or any combination of uppercase and lowercase characters will produce identical results.
Google may exclude common words
Google may ignore very common words in a search. Example of common words: 'the', 'or', 'a', 'is', 'how', 'what'. There are some rules regarding the exclusion of common words from a query.
(1) Very common words are excluded when there are other search terms within the same query. Try this example: what. All hits shows at least one occurance of the word 'what'. Now search for what date. Notice that Google drops 'what' from some of the results.
(2) Google will attempt to include all common words if there are only common words within a search. Example: is or what the. Not all hits will contain all the search terms.
(3) All words within a search phrase will be included, provided that the search phrase has at least two search terms. This is the only way to ensure that Google will include common words. Example: "is or what the" will force Google to return hits that contains the exact phrase.
(4) Google may ignore common words even if the + operator is used. The same applies for single word search phrases. Try these and observe the results: +is +or +what +the and "is" "or" "what" "the".
Google expands search terms when necessary
Search for dates. Notice Google expands the search term to include 'date', 'dating', or more. This feature is a double-edged sword. It may help to make your search more exhaustive, but it can also produce unpredictable results. Use the NOT operator to exclude unwanted search terms.
