Monumentation as a noun is the act of establishing a physical ["monument"] (such as a benchmark disk) at a measured location. This usage is commonly seen as "monumentation date".

The word monumentation is an adjective in the term [http://www.ngs.noaa.gov/PC_PROD/DDPROC4.XX/dformat.documentation.html#A.12 monumentation code] where all the types of monuments recognized by the ["NGS"] are listed.