What are the Rules for Regular Identifiers

What are the Rules for Regular Identifiers?

Rules for Regular Identifiers:

These rules are dependant on database compatibility level. For a compatibility level 90, following rules may apply:

a. The first character must be of the following:
- Letters as defined by Unicode standard 2.0 including latin and other characters from other languages.
- Underscore (_), Hash (#) or at (@) symbol with each having a significant meaning.

b. Remaining characters can be letters (Unicode 2.0), decimal numbers, basic latin or other scripts, #, $,@ symbols.

c. Identifiers must not be keywords reserved by SQL.

d. Embedded spaces or special characters are not allowed.
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