It extends to other products, not necessarily produced by TSR, if they provide information on the campaign world of Mystara. A few products have also been included which are compatible with Mystara. So while novels, computer games, home-spun adventures and products adventures and products from other companies are or can be included, products like miniatures or the SpellFire! At this time, only the net resources at TSR are provided, but there is a wealth of information provided by Mystara fans on the web.
Definition of Terms Explicit - The item is directly and explicitly placed in Mystara. Implicit - The item does not define where in Mystara it exists, but is linked to Mystara because it is part of the same series, or contains material which is only found in Mystara.
Compatible - The item is not set within Mystara, but is compatible with and easily placed in Mystara. Thunder Rift material is not included, due to personal prejudice. Suggested - The item is not quite compatible, but methods and suggestions are made so that the item can be placed in Mystara. For example, Planescape or Ravenloft products may include a character or setting from Mystara.
Unknown - At this time, I do not know if the product is related to Mystara or not. Vapourware - The material was announced by TSR at some point in time, but in fact the project was never completed nor published.
Some of the products here were retroactively placed in Mystara. AC6 is not included because it only contained player character sheets, and there never was an AC8. Although much of the information in the almanacs were reprinted material, they provided a timeline of events for each year.
An Index to Mystara Products
While the overall plot is similar, the orange version provides a different location for the setting, providing a new map and adds a new political entity. Note, I am not including the Domesday Book 13 issue, which has an article on Blackmoor.
I don't know for sure, but I believe that the information contained in that magazine was most likely included in the DA modules or in the Judges Guild supplement.
I have added an appendix at the end for those who don't know what the Domesday Book is. Most invisible ink pens have dried out since these were printed, but efforts are underway to reveal the text and print them online, if WotC doesn't publish them first.
Check the Downloads section. Only differences between these and B7 are minor edits. This pair, however, did make it clear that the elves had an Islamic background.
All Dungeon magazine contains is adventures, so I have eliminated the Description classification. Although set in its own campaign world, the city could be moved to Mystara. Note that the IBM PC compatible game is not included in this list, as it only contained information taken from the various Gazetteers.