5.4.15 Magnetic office dictation formats In the decades following World War II a wide variety of magnetically recorded office dictation formats appeared. That the needs of the office differ from other audio recording environments is reflected in their design: reduced size and weight, ease of operation and variable speed were prioritised, usually at the expense of audio quality. Magnetic dictation systems may be broadly divided into tape and non-tape-based formats. Tape in this context includes various forms of wire (see 5.4.14 above), reel and cassette. Some formats may be playable using standard equipment (non-standard cassette formats may sometimes be rehoused and replayed in standard cassette shells for instance) while others may only be played on dedicated format-specific players. Where a choice is available, a decision needs to be made between the two approaches. One entails the use of high- specification, relatively easy to maintain standard equipment, potentially coupled with poor compatibility in tape width, head configuration, replay speed, equalisation, noise reduction etc. The other offers higher compatibility between carrier and player, but very likely at the cost of the lower specification and esoteric maintenance needs of the original format-specific equipment. Tape-based formats can be subdivided into linear and non¡linear speed. The former will present fewer problems if replayed on conventional equipment; the latter may also be playable in this way, but will require speed adjustment (see 5.4.9). Non-tape formats include a bewildering array of discs, belts, rolls and sheets, all featuring magnetically coated surfaces, recorded onto and replayed using heads similar in principle to conventional tape heads. Given sufficient expertise, time and money therefore, it may be possible to build replay devices for some of these formats, incorporating components from more common tape replay equipment. In many cases however locating an original replay machine might be more feasible, and it may be possible to contract a specialist equipped to carry out the work.