The Reference Desk/The Anglican Regiment / The Anglican Marines

Where did these terms come from? Are they narrative, extra-narrative, or speculation?

• The articles for Demons Run, the Battle of Demons Run, and The Church mention either the Anglican Regiment or the Anglican Marines.
• I don't recall this term being used in the main television narratives, A Good Man Goes to War and The Time of Angels/Flesh and Stone, or any of the associated TV media.
• I do not have experience with any non-tv narrative or non-narrative source for this term. That's why I'd like some input.
• The only reference I remember is the Fat Man saying they're Anglican. While this is definitive that Anglicans are part of the force, it's not clear enough that this is also the name of the regiment or a type of marine.