* Keyword begins with `keyword:`, followed by a string.
* Keyword begins with `keyword:`, followed by a string.
* Regular expression begins with `regex:`, followed by a valid regular expression (per Golang's standard).
* Regular expression begins with `regex:`, followed by a valid regular expression (per Golang's standard).
* Full domain begins with `full:`, followed by a domain.
* Full domain begins with `full:`, followed by a domain.
* Domains (including `domain`, `keyword`, `regext` and `full`) may have one or more attributes. Each attribute begins with `@` and followed by the name of the attribute.
* Domains (including `domain`, `keyword`, `regex` and `full`) may have one or more attributes. Each attribute begins with `@` and followed by the name of the attribute.