S.F. do not wear civilian clothes. CIA is sometimes confused with this. Specops works closely with CIA and they sometimes go in together.
There are also "Black Ops." but I will bot comment further about them.
One more thing to add. The Geneva Convention clearly spells out procedure. Military Forces cannot attack enemy soldiers wearing cililian clothing. This is just what the Iraquis are currently violating. S.F. are strictly classified as "Military Forces".