Each type of node has its own set of legal properties, and each property has a type. This type may be a general type—number, flag, or string—in which case settings for the property are coerced to the correct type. An error is raised if they can't be coerced. Alternatively, the property reference may specify the range of legal values, such as Discard, PairAndDiscard, and IncludeAsText, in which case an error is raised if any other value is used. Flag properties should be read or set by using values of true and false. (Variations including Off, OFF, off, No, NO, no, n, N, f, F, false, False, FALSE, or 0 are also recognized when setting values, but may cause errors when reading property values in some cases. All other values are regarded as true. Using true and false consistently will avoid any confusion.) In this documentation's reference tables, the structured properties are indicated as such in the Property description column, and their usage formats are provided.