Coverage (information systems)
The Coverage of an Information system is a criterion for the completeness of the records in the information system. It is defined as the ratio of the number of instances/records in the system (mostly implemented as a Database) that represent real world entities  and the number of entities that exist (in the real world) and should be represented in the information system according to its purpose. Example: If there are 170 countries in the world and an information system holds 153 country records then the coverage of countries of this information system is 90%.
The Coverage of an Information system is a criterion for the completeness of the records in the information system.
It is defined as the ratio of the number of instances/records in the system (mostly implemented as a Database) that represent real world entities  and the number of entities that exist (in the real world) and should be represented in the information system according to its purpose.
Example: If there are 170 countries in the world and an information system holds 153 country records then the coverage of countries of this information system is 90%.

Bibliography
https://www.phil-fak.uni-duesseldorf.de/fileadmin/Redaktion/Institute/Informationswissenschaft/stock/271.pdf
Hood, William W.; Wilson, Concepción S. (2003). "Informetric studies using databases: Opportunities and challenges". Scientometrics. Springer Science and Business Media LLC. 58 (3): 587–608. doi:10.1023/b:scie.0000006882.47115.c6. ISSN 0138-9130. S2CID 12388738.
Naumann, Felix; Freytag, Johann-Christoph; Leser, Ulf (2004). "Completeness of integrated information sources". Information Systems. Elsevier BV. 29 (7): 583–615. doi:10.1016/j.is.2003.12.005. ISSN 0306-4379.