These features are derived from the type 4 record (Index to Alternate Feature Identifiers), and relate a TLID to 1 to 4 alternate feature name numbers (the FEAT attribute) which are kept separately as FeatureIds features.
The standard reader pipeline attaches the names from the FeatureIds feature attributes ALT_FEDIRS, ALT_FEDIRP, ALT_FENAME, and ALT_FETYPE to the CompleteChain features. The ALT_FENAME is a list of feature names associated with the TLID on the AltName feature, with the alternate names separated by commas.
Note that 0, 1 or more AltName records may exist for a given TLID and that each AltName record can contain between one and four alternate names. Currently CompleteChains will only be updated with the alternate names from one of the related AltName records, potentially resulting in the loss of some alternate names. Future versions of the TIGER/Line reader will add support for multiple AltName records.
These features have no associated geometry.