Hi DP24PH, Thank you for reaching out. I was trying to follow the OSM wiki’s parking_aisle page (service=parking_aisle), where it mentions parking aisles should not be used for the main “trunk” of the parking lot or the entrance/exit roads. Following this guidance, it seems some of these single road parking lots would be better mapped with only a highway=service tag and an amenity=parking polygon to represent the parking lot.

Hello user_5359. This admin_level tag was added back in 2012 by the user kartalakopang, who has done a lot of mapping in the country. The wiki does not mention a level 99: boundary=administrative#admin_level.3D.2A_Country_specific_values and I can’t find a place that says what admin_level 99 means, so maybe it is something local. It looks like other mappers are adding this in Indonesia (way/168085702/history; way/560600960/history), so you may want to ask them for more information.
Best.