When Sony devised a naming system for their U-matic line of tape, they made it needlessly complicated.  Here is a brief summary of how to identify tapes by their name.  A description of what the tapes are intended for is in the sections below.

First let it be known that there are 2 sizes of U-matic cassette.  The larger of the two is intended for use in the table top editing decks and has a larger capacity.  The smaller tapes were designed to fit inside the portable recorders that went into the field.  The bigger tapes, KCA tapes, will not fit in the portable recorders which use the smaller, KCS tapes.  This naming system works for all BRS and XBR tapes.  However, tapes for the SP U-matic machines use a slightly different system.  Inseted of having KCS or KCA, all the tapes start with KSP.  The difference is that the small tapes will have a title like,  KSP-S20.  This is a small 20 minute tape intended for used in an SP portable machine such as a VO-8800.  The larger SP tapes would be noted as KSP-20.  The graphic below is an illustration for all of the visual learners out there.

XBR tape was originally intended for use in high-band machines, however, it is suitable for low band machines as well. Its intended use is for making master copies of films or commercials.  Its high density and wide band width allow for it to be copied many times without having any loss of quality on the copies of the tape.  This tape quality coupled with the quality of the U-matic machines allow for a recording that is equal to anything currently on the market today. 

BRS (Broadcast standard tape) is primarily used for multiple playback situations.  When commercials are played over and over at a TV station, BRS tape is used.  This tape is designed to be more abrasion resistant than the others so it can maintain contact with the rotating head for longer periods of time.  These tapes were intended for use by TV stations and the professional field, i.e. multimedia presentations for business. 

SP format tape was intended for the newest U-matic machines.  These machines are the BVU-900 series, VO-8800, VO-9800, and VO-9600.  This format of tape is a higher grade than XBR and BRS and produces a superior quality recording when used in conjunction with a U-matic SP machine.  However, these tapes are perfectly suitable to use with other machines, and will produce adequate results.