

(I’m not a lawyer, this comment should not be viewed as a credible source)
They probably mean professionals that are hired by clients on a retainer agreement as opposed to working for an employer on a permanent or semi-permanent basis. Legal advice, legal representation, financial advice, personal assistants, individual contractors, and so on.
One could make the argument that since the retainer is not an employment contract, and the retained professional is not one of many employees (instead usually individuals or small teams), then collective bargaining doesn’t make sense. The difference is that the retainer agreement is much more specific and favors the person whose services are retained, compared to employment contracts and labour laws in the USA. It’s also a legally binding contract and the client can be taken to court if it is breached (e.g. by withholding payment).
On the other hand, if those people are also employed by a company (e.g. a non-partner associate in a law firm) or employ other people in turn, then those people can (and should) also benefit from collective bargaining.











That’s just Python’s generator syntax. Not all that difficult to parse once you get a feel for it. Plus syntax highlighting helps.
(OUTPUT_EXPRESSION for ITEM in INPUT_ITERABLE if CONDITION)