digit strings as table indexes

[Jimmie Houchin <jhouchin@...>]

Okay, I learned that '000' is not a valid name in Lua.
But for whatever reason it is accepted successfully as a table index.
I don't if that is something I can depend on or not.

If I don't care about losing the syntactic sugar of t.000 for access,
are there other inherent problems with using digit strings to index tables?

I don't have a lot of programming experience, so I am looking for some 
wisdom from those who are further down this journey.

So many things are identified by numbers, products, people, books, etc.
Numbers as unique identifiers are common. And especially since nothing 
starting with a digit is a valid name, regardless of subsequent 
alphanumeric characters. That invalidates lots of ids for objects.

But I don't know if I'll run into problems continuing down that road.

I don't want to build a huge people database indexing them by their SSN 
(U.S. Social Security Number) and then find I am using poor practices.

Would it be better, even if seemingly uglier (to me) to use
'ssn123-45-6789' instead of simply '123-45-6789'
which would make the digit string into a legitimate Lua name.

Any wisdom, knowledge and understanding greatly appreciated.

Thanks.

Jimmie