What does FXS stand for?

Fine-Focus X-Ray Series (SAUS)

Foreign Exchange Station (SAUO)

Foreign Exchange Subscriber (SAUO)

Forts - Telegraphy (PCTE)

Fox Sparrow - Ornithology

Fragile X Syndrome - Genetics

Future Experimental Sport - Automobile model designation

Inflatable Systems Inc., Orange, CA - Manufacturer code for watercraft hull identification number (USCG)