(Land lots zoned in Seattle, Washington city limits)

Single Family Zoning (Lots zoned Single Family)

SF 9600 - Single-family 9,600  
SF 7200 - Single Family 7,200  
SF 5000 - Single Family 5,000  

(SF 5000 means one single family home per 5,000 sq ft of land)

Multi Family Zoning (Lots zoned Multi-Family) 

LDT - Lowrise Duplex/Triplex.   You can build one unit per 2000 square feet of lot.
L1 - Lowrise one. A density of one unit per 1600 Square Feet of lot, 25 foot height limit with a 10' allowance for the roof.
L2 - Lowrise two. A density if one unit per 1200 SF of lot, 25' height, 10' allowance for roof..
L3 - Lowrise three. A density of one unit per 800 SF of lot, 30' height limit, 5' for roof pitch.
L4 - Lowrise four. A density of one unit per 600 SF of lot, 37' height limit, 5' roof pitch.
MR - Midrise. No density limit, 60 foot max with 5' for the roof pitch.
HR - Highrise. No density limit, height does have limits, but mainly its a function of finances limit.

Commercial Zoning (Lots zoned commercial)

NC1 - A small shopping area that provides primarily convenience retail sales and services to the surrounding residential neighborhood.
NC2 - A moderately-sized pedestrian-oriented shopping area that provides a full range of retail sales and services to the surrounding neighborhood
NC3 - A larger pedestrian-oriented shopping district serving the surrounding neighborhood and a larger community, citywide or regional clientele; allowing comparison shopping among a range of retail businesses
(NC250 would be a Neighborhood Commercial 2 with a 50' heigh limit.)

C1 - An auto-oriented, primarily retail/service commercial area that serves surrounding neighborhoods as well as a citywide or regional clientele
C2 - An auto-oriented, primarily non-retail commercial area, characterized by larger lots, parking, and a wide range of commercial uses serving community, citywide or regional markets

Industrial Zoning (Lots zoned industrial)

IG1 - The purpose of the IG1 zone is to protect marine and rail-related industrial areas from an inappropriate level of unrelated retail and commercial uses by limiting these uses to a density or size limit lower than that allowed for industrial uses.
IG2 - The intent of the IG2 zone is to allow a broad range of uses where the industrial function of an area is less established than in IG1 zones, and where additional commercial activity could improve employment opportunities and the physical condition of the area, without conflicting with industrial activity.
IB - The intent of the Industrial Buffer is to provide an appropriate transition between industrial areas and adjacent
residential zones, or commercial zones having a residential orientation and/or a pedestrian character.
IC - The intent of the Industrial Commercial zone is to promote development of businesses which incorporate a mix of industrial and commercial activities, including light manufacturing and research and development, while accommodating a wide range of other employment activities.