Not sure about was. It is an internationally accepted abbreviation for milligram.
Sr. is the abbreviation for señor in Spanish
The written abbreviation for "señora" in Spanish is Sra.
Esp.
Usually the abbreviation for Spanish in an English-speaking context is "SP." The abbreviation for Spanish in an international context is "ESP" or "ES".
The abbreviation is (sq. ft.) I do believe.
Kilograms can be written as "kg," which is the internationally recognized abbreviation for kilograms.
None.
Blvd
Dr.
Sra.
Aniv.