@demobox Really don't know :) Apparently it is the ISO code for Seattle according to Softlayer, in fact  `listLocations` returns the following entries:
```
Datacenter{id=18171, name=sea01, longName=Seattle, locationAddress=Address{id=3, country=NSFTW, state=IL, description=208.100.0.117}, regions=[[keyname=FIRST_AVAILABLE, description=First Available], [keyname=SEATTLE, description=SEA01 - Seattle - West Coast U.S.]]}, 
Datacenter{id=37473, name=wdc01, longName=Washington, DC, locationAddress=Address{id=4, country=US, state=VA, description=Washington DC - WDC01 - Chantilly}, regions=[[keyname=WASHINGTON_DC, description=WDC01 - Washington, DC - East Coast U.S.], [keyname=FIRST_AVAILABLE, description=First Available]]}, 
Datacenter{id=138124, name=dal05, longName=Dallas 5, locationAddress=Address{id=722, country=US, state=TX, description=Dallas - DAL05 - Corporate HQ}, regions=[[keyname=DALLAS05, description=DAL05 - Dallas - Central U.S.]]}, 
Datacenter{id=168642, name=sjc01, longName=San Jose 1, locationAddress=Address{id=1822, country=US, state=CA, description=San Jose - SJC01}, regions=[[keyname=FIRST_AVAILABLE, description=First Available], [keyname=SANJOSE, description=SJC01 - San Jose - West Coast U.S.]]}, 
Datacenter{id=224092, name=sng01, longName=Singapore 1, locationAddress=Address{id=2982, country=SG, state=null, description=Singapore - SNG01}, regions=[[keyname=SINGAPORE, description=SNG01 - Singapore - Southeast Asia]]}, 
Datacenter{id=265592, name=ams01, longName=Amsterdam 1, locationAddress=Address{id=3322, country=NL, state=null, description=Amsterdam - AMS01}, regions=[[keyname=AMSTERDAM, description=AMS01 - Amsterdam - Western Europe]]}
```