Clarification: Members vs members

There is a line in rule 11 - Parties: "Any Lord in a Party and not Speaker of that Party is referred to as a Member."

Does this mean Speakers aren't included when we indicate, "members of a Party?" Is there a difference between a Member and a member?

We use capitalized keywords by convention, but it might be good to make a glossary entry explaining that a keyword supercedes the normal english usage of a word.