Linear referencing systems Referencing Systems (LRSs) are how locations are specified and they vary from client to client. The Location Reference field is shown in the Settings menu if the security profile of the user allows access to all configured LRSs. If the security profile only allows access to one LRS, then this LRS is always active and cannot be changed, so there is no need to display the Location Reference field. An LRS can be assigned to a security profile in Access Profiles. The contents of the LRS field are configured in the Setup LRMs Window.
...
Basic LRS: This is the default method of specifying locations and is always provided. With this type of referencing system, the system knows the location of assets in only one way, which is route and mile point.
Note Note: For For the Basic LRS, alternate locations (aliases) may be specified for principal locations in the Concurrent Location window. - Alternates: In addition to the Basic LRS, some agencies use other ways to identify locations. This field includes these other methods. This allows you to choose the method of identifying a location that works best for your agency. A typical alternate LRS is street name and block number.
...