An old, but still-used designation for a twisted-pair cable with foil shield. However, the designation does not specify whether the shield type refers to individual pairs or the cable as a whole.

New and more precise designations are set forth in the ISO/IEC 11801 (2002) E standard and take the form of XX/YZZ, as follows:

XX indicates the overall shield

• U = unshielded
• F = foil shielding (coated plastic foil)
• S = braided shielding (braided wire)
• SF = braided and foil shielding

Y indicates the shielding of the individual pairs

• U = unshielded
• F = foil shielding (coated plastic foil)
• S = braided shielding (braided wire)

ZZ is the twisting type

• TP = twisted pair (usually)
• QP = quad pair

Example: An F/STP cable is a Foiled Shielded Twisted Pair (foil shield for overall cable and braided shield for pairs).