The syntax for a label is an asterisk followed by an identifier (alphanumeric string with alphabetic initial character).

This can be any alphanumeric string up to 28 characters in length.

Blank nodes are represented by an alphanumeric string, prefixed with an underscore and colon ().

Common data types may include: integers, booleans, characters, floating-point numbers, and alphanumeric strings.

Committing several dozen patternless alphanumeric strings to memory and changing them several times a year?

So they're saying "Unique Identifier, an alphanumeric string unique to each device based on various hardware details.

A number or alphanumeric string usually identifies the newer commercial varieties.

An aircraft registration is a unique alphanumeric string that identifies an aircraft, in similar fashion to a licence plate on an automobile.

A typical data hash will process an input file to produce an alphanumeric string unique to the data file.

Character entity references can also have the format where name is a case-sensitive alphanumeric string.