When you reference parts of the pattern, you do so by naming them. The names you give the different parts are called identifiers.

In this example:

START n=node(1) MATCH n-->b RETURN b

The identifiers are n and b.

Identifier names are case sensitive, and can contain underscores and alphanumeric characters (a-z, 0-9), but must start with a letter. If other characters are needed, you can quote the identifier using backquote (`) signs.

The same rules apply to property names.