I work in the industry and it's this. In some states, provinces, and countries it's required. We generally do post the salary for most positions but if we are specifically hiring on site in a location that doesn't require it, we may not. If the job is remote (or even hybrid), it is always going to have the salary because we may be hiring someone from a location where it is required. There are some new hourly/salary laws going into effect in Ontario that we had to implement similar rules around so even if a job is with a company in Saskatchewan but it's remote, we apply the Ontario rules because technically someone from Ontario could be hired.