Some of the special characters described in the Warhammer Armies books and Campaign supplements have unique magic items - items which they and they alone can use. As the complete rules for these characters are included in the appropriate supplements, no cards are included in Warhammer Magic to represent their unique magic items. As no other models can use these items it was felt unnecessary to include cards for them.
However, unique items in existence at the time of writing have been included in a separate section of the magic items summaries so that players can conveniently refer to them. Bear in mind that further special characters may well have new items not included in the summary because they were created after the publication of Warhammer Magic.
We do not intend to invent more magic items which can be used generally. We may well invent items specific to special characters or specific to particular campaign battles. As the use of special characters is ideally a matter of prior agreement by the players, this means that Warhammer Magic contains all the magic items available to armies in the general run of things.