When defining features, XFM makes a distinction between primary features and sub-features. Primary features exist as independent entities within a session. Sub-features have a parent relationship with another feature and only exist within the context of their parent feature. A common sub-feature is annotation.

XFM feature naming rules:

• Name is composed of alphanumeric characters.

• Invalid characters are space ( ) $ # < > ’ “ \ / ? * | , = & . + - ^ ~ ! ; : [ ] { } @ % \n \t ` "

• Name must be a valid XML node name and cannot start with a number.

• During import of legacy GeoGraphics projects, invalid characters and starting numbers are replaced with underscores.

• When feature definitions and feature instance names are loaded into Bentley Map, invalid characters are converted in memory to underscore characters. This also applies when feature names are inferred from level names.

• Duplicate names are created with incremental numbers. For example, if a Road feature exists and a second is created with the same name, the second is named Road_1, a third would be created as Road_2, and so on.