Pretty much. Article II of the Chapter 27 governs non-conforming uses. A use is non-conforming and "grandfathered in" if "a building, structure or the use of land was lawfully established if it was in existence prior to June 6, 1923, or was established in conformance with the zoning ordinance in effect at the time the use was established."
There is a specfic provison for parking, Section 205, which provides
"A building or structure is considered nonconforming by parking if the lawfully established use of the building or structure does not meet the parking requirements of Article VII.
205.1. Addition, enlargement, expansion and intensification. A building or structure nonconforming by parking, may be added to, enlarged, expanded or intensified provided additional parking space is supplied to meet the requirements of Article VII for such addition, enlargement, expansion or intensification. The number of additional parking spaces supplied shall be the difference between the number of spaces required for the building or structure including such addition, enlargement, expansion or intensification, and the number of spaces required for the previous use of the building or structure; each calculated in accordance with the requirements of Article VII. "
So basically if you were grandfathered in, and you have don't expand the building you don't have to provide parking. If you do expand your building, you have bring the parking up to code.