How creative workers are counted

The DCMS classifies enterprises and occupations as creative according to what the enterprise primarily produces, and what the worker primarily does. Thus, a company which produces records would be classified as belonging to the music industrial sector, and a worker who plays piano would be classified as a musician.
The primary purpose of this is to quantify - for example it can be used to count the number of firms, and the number of workers, creatively employed in any given location, and hence to identify places with particularly high concentrations of creative activities.
It leads to some complications which are not immediately obvious. For example, a security guard working for a music company would be classified as a creative employee, although not as creatively occupied.
The total number of creative employees is then calculated as the sum of:
all workers employed in creative industries, whether or not creatively occupied (eg all musicians, security guards, cleaners, accountants, managers, etc working for a record company)
all workers that are creatively occupied, and are not employed in creative industries (for example, a piano teacher in a school). This includes people whose second job is creative, for example somebody who does weekend gigs, writes books, or produces artwork in her spare time