From Free Content Friday Vol. 001: The GM's Toolbox: The Resource Catalog Introduction:
When running games of Outbreak: Undead, a crucial component of the game is the gathering and spending of Resource by the players. There is generally a question as to what a character would be able to find and subsequently purchase with the Resource they find. Under most circumstances, the rules in the book are more than sufficient at covering a broad range of common items that can be found in the garage, storeroom, behind counters, etc. But this may not be enough for the GM who knows a location well enough to know precisely what is available and in roughly what quantity. Also, a GM who desires to inspire a higher degree of fear in their players by making certain resources extremely finite (even those that are otherwise common) would benefit from adapting the rules in the Outbreak: Undead core rulebook to incorporate such a frightening reality. An entirely optional, but efficient, way to accomplish this is by using a "Resource Catalog".
A "Resource Catalog" is a list of what a character is able to purchase with their available Resource. What is on this list is based on the locations that the characters loot during missions or what kind of location they are in when the game starts. For most scenarios, the items are automatically added to the catalog once the location is successfully searched. The master list that a can be purchased from when characters are in their Stronghold is the "Strongohld Resource Catalog". Otherwise, purchases can only be made in the location they are found in.