There are two tabs for cheaper Special Abilities. One the first all you can do is select Special Abilities from a list. Selecting a Special Ability makes the Ability cheaper every time the character buys it. For example if you select Armor Use I, the character will be able to buy Armor Use I several times, for different armors, and always at half cost.
There is a special option 'a topography', you can select. If you check this option the player can select a topography that will be cheaper for the character.
On the second tab you can select a variant and a description for the Special Ability. One of them must always be given. Selecting a Special Ability on this tab makes only one variant of the Ability cheaper for the character. What variant is cheapened is always selected by the player, so it doesn't make too much sense to enter a specific variant, but you can enter a description of the variant as variant. For example for Knowledge of a Place you could enter "a quarter in the home town" or "a place to go into hiding" this can than be replaced by the player.
The description can be used to make clear, that the variant is selectable by the player. The description is shown when selecting the culture/profession at character creation. For example if you select Culture Lore as cheapened and don't enter a description it would be shown as "Culture Lore (Almada)", which is misleading, as the player can select the culture. To prevent this you can enter a description like "a free selectable culture lore". Another example would be Armor Use I. When selected as cheapened, without description, it would be displayed as "Armor Use I (variant)". In that case you could enter "Armor Use I" as description.