Expertise or advanced equipment lets members of the Organization buy a selected collection of items at a discount, chosen from a Catalogue. You can only choose common items. Members of the Organization can purchase those items in town for a discounted price.
Minor. For each two levels, add either two consumable items or one permanent item of up to that level to the Catalogue. At level 1, add a 1st-level item. At level 3, add another item of 3rd level or lower, and so on. Reduce their price by 10%.
More info in 05 - Player Organizations.