Before learning Google's more advanced operators, we have to keep in mind some general rules.
Advanced operator syntax
An advanced operator has the following syntax: advanced_operator:search_term or advanced_operator:"search_phrase". These are the only two correct ways to use an advanced operator.
There cannot be any spaces between the advanced operator, the colon, and the search term or search phrase. A space between any of them will change the advanced operator into a search term.
Example of correct usage: inurl:money. All results have the word 'money' in their URL. Add a space in between: inurl :money, the inurl operator becomes a search term. Try it.
The search term or phrase to be used with an advanced operator follows the same general search rules.
Basic operators that are added in front of a search term will be ignored. Example: inurl:+money is the same as inurl:money. Another example: inurl: +money. inurl becomes a search term and 'money' becomes just an ordinary forced-include search term.
Basic operator combos
Combination of an advanced operator with multiple search terms that use basic operators follow the basic operator rules that has been covered until now.
A correct example: insurance +inurl:money -bank. Submitting this tells Google to show results that has 'insurance' in title, text or URL, to show results that must have 'money' in URL, and not to show results that has 'bank' in title, text, or URL.
Using the + operator with an advanced operator search phrase will invalidate the function of the advanced operator. Compare these two results: inurl:"money tree" and +inurl:"money tree".
Advanced operator combos
Advanced operators can be combined into a single search and basic operators can be used as well. They follow the general search rules and the basic operator rules. However, do take note that not all advanced operators can be combined and some advanced operators cannot be combined at all.
