The Commissioner: shall create and make available a summary of this subtitle; and may create and make available a summary of regulations adopted under this subtitle. On request of an employer, the Commissioner shall provide without charge: a copy of this subtitle; a summary of this subtitle; a copy of regulations adopted under this subtitle; and if the Commissioner has developed a summary of regulations adopted under this subtitle, a summary of the regulations. Each employer shall keep posted conspicuously in each place of employment: a summary of this subtitle that the Commissioner has provided to the employer; and a copy or summary of regulations adopted under this subtitle.