In addition to the most known magnetic cards manufactured by main firms, there are several other kinds of phonecards which use this system, developed in different ways, even if most of them have a ferrite strip across them, that could be horizontal or vertical, on which is stored the units, recognition signals and other information rather like on the tape of a tape-recorder or video.
Some of them include DLRCT cards, that show a 12mm magstripe near the top of the card on the reverse, which have been widely used by Denmark; Pay-Tel paperboard cards used on board of ships and trains in Australia, and in Nauru; plastic cards used in Bulgaria and manufactured in Germany; paper cards used in Romania, Ireland, Sweden, Malta and Russia; thin cards manufactured by Telkor and gone on trial in Some Countries.
Other smaller manufacturers exist but they have met with limited success in the field of telecommunications.
