Names (field names, for example) are case-insensitive and consist of multiple words, numbers, or hyphens. A name should start with a word and should finish with either word or number.
Name parts can be separated by any number of space characters (Unicode Zs, not a new line characters), but this is not always required and sometimes prohibited or discouraged (may be so with hyphens).
Space is not a part of the name. Rather it’s just a syntactic method of separating different parts of the name.
Word is a sequence of any Unicode letters.
These are valid words:
When the name contains two sequential words it is necessary to separate them by space, like this:
A number is a sequence of decimal digits (
The name can not start with a number. So, the following is not a valid name:
When the number follows a word, there is no need to place the space between them. So the following names are the same:
The same rule applies to the word following the number. The following names are the same:
render 3 d
Names may contain hyphens (
-). There are multiple hyphen characters in
Unicode. o42a makes no difference between them internally, but applies
different syntactic rules for the sake of grammatical correctness. The following
hyphen symbols recognized:
| U+002D | HYPHEN-MINUS |
| U+2010 | HYPHEN |
| U+2011 | NON-BREAKING HYPHEN |
The following rules apply to the hyphen usage in names:
- the name should not start with a hyphen,
- the name should not end with a hyphen,
- the hyphen should not follow another hyphen,
- no spaces allowed before HYPHEN-MINUS,
- a space before HYPHEN or NON-BREAKING HYPHEN is discouraged and issues a warning,
- a space after NON-BREAKING HYPHEN is discouraged and issues a warning.
To write a subtraction operator or unary minus operator, just place a space before the HYPHEN MINUS sign.
So, the following are not a valid names:
plug - in
Examples of valid names: