The InDoc Centre maintains records of immovable cultural heritage in the territory of the Republic of Slovenia. Archived documents dated prior to the year 1913 were recorded by the Central Committee for Research and Protection of Built Monuments of the Austro-Hungarian Royal Imperial Archives from Vienna. Between 1913 and 1919 records were kept by the Central Committee for the Protection of Monuments in Carniola. Later on, the state (republic) authorities of the Kingdom of Yugoslavia (1919–1941) and Socialist Yugoslavia (1945–1991) maintained records.
Today, the INDOK Centre keeps only records on nationally important monuments, others are kept in regional units of the Institute for the Protection of Cultural Heritage which were established between 1957 and 1981.
Because of their content, age, and uniqueness, most documents archived in the INDOK Centre are submitted to the special status of state archival protection. Depending on the nature and material of the documents, different archives are formed: photo archives, archive of urban plans, building and renovation plans, paper documents, contracts, conservation and restoration elaborates, databases of legal acts.
Documents are being digitalised and a database on immovable cultural heritage is being updated into an information database system of cultural heritage.
The first unit of today's Special Library for the Protection of Cultural Heritage at the INDOK Centre was established in 1913 by the Central Committee for the Protection of Monuments in Carniola. The library is open to researchers and experts in the field of heritage protection. The library consists of some 13,500 monographs and 340 titles of current expert periodicals and of some 10,000 historical periodicals on immovable heritage protection.