The total number of items that can be known is determined by the character's knowledge points and measure of expertise.
These are "studied artifacts," the accumulated list of items the character has knowledge about.
The total number of known items will equal 1 item per 4 points of knowledge above 9, plus 1 additional item per 3 points of knowledge above 19. Thus, a character with 14 points of knowledge would have useful knowledge of 5 artifacts; a character with 24 points would have useful knowledge of 20 artifacts (15+5).
The character will possess knowledge relating to the item's probable present location, as well as the importance of combining an items with others to obtain more powers. The character will know the item's supposed present user, the building or city where the item is kept and the organization that keeps it secret. If the item is lost, the time and place when the item was last used or lost will also be known.
The character will also know the general history of the item, it's place of origin, method of manufacture and myths associated with its appearance.
Finally, the character will have a basic working knowledge of the item's primary power - weapon's bonus, magical energy or measure of force. Typically this will extend to only one power, but the DM may conclude that certain items are known for dual abilities.
Which items are known will be randomly chosen from this list of artifacts.