Rituals - Scope

Back to pondering how to scope the Rituals Project.

Looking at the full definition from the OED I have in front of me;

"1. A religious or solemn ceremony involving a series of actions performed or according to a or prescribed order. 2. a series of actions habitually and invariably followed by someone."

Now, you could say that commuting to work is a ritual but if you allow something like that then the scope becomes so wide as to become pretty meaningless.

I've concocted three rules to hopefully keep the scope as narrow as possible without excluding anything interesting.

1. Done by choice.

2. Not simply a practical act.

3. Imbued with an external significance.

I feel those rules will define the project, but what do you think?  What falls within that scope?  Does it need to be narrowed further or is it perhaps still too broad?