This document is an intro to LER use cases. LER use cases are aggregations of a subset of use cases developed by the CLWMR and are included in its project charter. The use cases support the needs of three broad primary audiences: (1) learners and workers; (2) education, training, and credentialing organizations, and (3) employers. This subset is aimed at the needs of learners and workers that cross-cut education, workplace, and military domains. Initially, these use cases are being used by the T3 Network Map and Harmonize Data Standards project, to set the context for mapping data standards across domains that concentrate on education and employment. An analysis of the data standards mapping will identify gaps in data standards for supporting these use cases. The T3 Network is not developing a new data standard but the outcomes from the analysis can be used by data standards organizations to determine potential updates to their standards.