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:

• The name can only be composed of alphanumeric characters. Lakes & Rivers will be come LakesRivers.

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

• Name must be a valid XML node name and cannot start with a number. A feature named 8p276-qbc will result in p276qbc.

• 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 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.