Custom properties are properties that you create and attach to an existing item type. If your site sells umbrellas, you might want to add properties to the product item type for diameter, color, and material, all of which are attributes of an umbrella that customers might want to know before making a purchase. Another example is adding properties Referral Source and Age to the external user profile.
Depending on how your item mappings are configured, custom properties may automatically display in the Details pane when an item of that type is selected. To learn how item types specify properties, see Specifying Properties to Display section. Locate the parent item view mapping and item view mapping and adjust their settings accordingly.
Also, update property groups so that your properties are visible in a property group used by the Multi Edit tab to edit items in bulk. See Creating and Defining Multi Edit Property Groups.
