Contributing ruleset recipes

[just randomly throwing stuff in here for now]

The character _ is placeholder for "current scope".

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The strictest ruleset for which recipes must un-break sites is:

• The global rule * 1st-party * allow is present
• The global rule * 1st-party frame allow is present
• All 3rd-party requests blocked by default (including images/css)
• All scripts blocked by default (including 1st-party scripts)
• All 3rd-party frames are blocked by default
• All stock hosts files are enabled

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For any given 3rd-party, if only one type of request is needed, then the rule should allow only that one specific type. Example:

_ someserver.cdn xhr

For any given 3rd-party, if more than one type of request is needed, two cases:

Case 1: If only passive resources are needed, then the rules should be specifically only for these passive resources. Example:

_ somescdn.com css
_ someserver.com image

Case 2: If active resources are needed, then a broad rule should appear before the more specific ones. Example:

_ somecdn.com *
_ somecdn.com script
_ somecdn.com frame

When a rule such as _ somecdn.com * is used in a recipe, there is no need to explicitly declare rules for passive content (i.e. no need for _ somecdn.com image).

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Using rules for hostnames which are public suffix or below is frowned upon, though it is sometimes impractical to stick to this rules. When this happens, a convincing argument in favor of the exception should be made.

In the same vein, type-based rules must be avoided. Bad:

_ * xhr

If ever this happens to be the only sensible solution to some real issue, then again a convincing argument should be made in favor of such broad rule.

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