Maryland Code, Tax-General § 11-701

(i) permanently or temporarily maintaining, occupying, or using any office, sales or sample room, or distribution, storage, warehouse, or other place for the sale of tangible personal property, a digital code, a digital product, or a taxable service directly or indirectly through an agent or subsidiary;

(ii) having an agent, canvasser, representative, salesman, or solicitor operating in the State for the purpose of delivering, selling, or taking orders for tangible personal property, a digital code, a digital product, or a taxable service; or

(iii) entering the State on a regular basis to provide service or repair for tangible personal property or a digital product.

(i) to engage in the business of an out-of-state vendor;

(ii) to engage in the business of a retail vendor; or

(iii) to engage in the business of a marketplace facilitator.