Editing LERG Routing Guide (section)

==Content and purpose==
The LERG provides data to support the routing of [[telephone]] calls by service providers in the [[public switched telephone network]] (PSTN) and the interconnection points of the PSTN with [[Internet Protocol]] (IP) networks. 

<!--  This is just a verbatim copy from a copyrighted document, reproducing it without explanation is not encyclopedic
Components include:
* Operating company numbers (OCNs), company names, routing contacts
* [[Country code]] assignments 
* Numbering Plan Area (NPA) code assignments ([[area codes]]) 
* [[Local access and transport area]] (LATA) codes 
* Destination code assignments (NPA NXX thousands-blocks) 
* [[Access tandem]] codes 
* Special NXX prefixes (e.g. 911, 976) 
* Switching entity record detail (e.g. equipment type, V&H coordinates), including PSTN and IP network elements 
* Rate center details (e.g. V&H coordinates) and localities (includes county and postal codes (US) of localities) 
* Switch homing arrangements (tandem and other switch-to-switch interconnections) 
* Operator [[access tandem]] codes (ATCs) 
* [[Location Routing Number]]s (LRNs)
-->