Coercivity is the property of a magnetic stripe that indicates its resistance to demagnetization.

 It is measured in Oersteds (Oe).

The coercivity of a regular credit card is about 300 Oe, and considered as low coercivity.

High coercivity (HiCo) magnetic stripe, however, usually has coercivity values ranging from 2500 to 4000 Oe.

High-coercivity cards are currently used in applications which need performance such as in critical test equipment.

HiCo is superior to LoCo in decreasing the chances of accidental data lost. However, due to the cost of encoding, LoCo technology is still very popular.

There are three tracks in magnetic stripe.

Track 1 and 2 are readable-only tracks, the information recorded in track 1 and 2 can only be read, but not re-writable, or modifiable.

Track 3 is both readable and writable.

Track 1 can record both numbers and characters, while track 2 and 3 can only record numbers.