The Content Standard for Digital Geospatial Metadata (CSDGM), Vers. 2 (FGDC-STD-001-1998) is the current US Federal Metadata standard. The FGDC originally adopted the CSDGM in 1994 and revised it in 1998. According to Executive Order 12096, all Federal agencies are ordered to use this standard to document geospatial data created as of January 1995. The standard is often referred to as the 'FGDC Metadata Standard' and has been implemented beyond the federal level with State and local governments adopting the metadata standard as well. Source: http://www.fgdc.gov/metadata/geospatial-metadata-standards
“The objectives of the standard are to provide a common set of terminology and definitions for the documentation of digital geospatial data. The standard establishes the names of data elements and compound elements (groups of data elements) to be used for these purposes, the definitions of these compound elements and data elements, and information about the values that are to be provided for the data elements.” Source: http://www.fgdc.gov/metadata/csdgm/introduction.html
More information: https://geo-ide.noaa.gov/wiki/index.php?title=Category:FGDC_CSDGM