Header Rules: Options & Syntax

I have been scanning these discussions about using words in the headers to develop rules to filter messages. The online help file (manual) offers only a basic description of rule construction. I want a complete list of valid ‘Name: Value’ pairs and a clear description of syntax. For example, the following is not obvious:

  1. When to use quotation marks – are they needed when using the ‘text: value’ pair;
  2. Use of commas and spaces between strings of ‘name: value’ pairs. How is the rule interpreted?
  3. What are the rules (guidelines) and the syntax for AND & OR options (commas between values or multiple lines)?
  4. Can I add multiple ‘searched words’ lines in a rule and are these treated as an AND or OR option? Must all lines be ‘true’ for the rule to be executed?
  5. Do all ‘value: pairs’ have to be entered as a single string to be treated as an OR list of options?

This information sort of exists in this forum but to construct a master list requires reviewing years of user questions. Even so, the syntax for how they are written and applied is not consistently clear or convincing. My test rules fail. Does a more technical list of the options for header rules exist? Can one be provided here?