The totality of preventive and retroactive measures for their preservation is called preservation.
Archiving, archives and repositories
In a broader sense, an archive is any collection of documents and objects that are not or no longer regularly used. This can include private records, film recordings, photographs or deeds as well as official documents, police files, church registers and the like.
In Germany, there are federal and state archive laws that regulate exactly what kind of official records must be kept, in what form, for how long, and at which institution. Authorities may not arbitrarily destroy or dispose of records that are no longer needed, but must offer them to the relevant archive. The latter decides on the basis of the applicable regulations whether the records are worthy of archiving.
The accessibility of documents contained in archives is also governed by a number of laws: due to data protection, many official documents can often only be viewed several decades after they have been stored, by the persons concerned or their relatives, after a request has been granted. In principle, however, a number of archives exist that are accessible to everyone: City and state archives, the Federal Archives and quite a few more. The service is used, for example, by historians, genealogists, pupils and students and private individuals who want to find out something about their homeland or their ancestors. However, use may be restricted to certain items in order to protect personal rights, and is also regulated by specifications on how the individual items are to be handled in order to protect the documents.
Climate, humidity and preventive conservation
In the preventive conservation of documents, temperature and humidity play an important role, in addition to light conditions and the deacidification of lignin-containing papers - both should not be subject to strong fluctuations and should tend to be kept low. Constant humidity devices help to keep the relative humidity at around 50%, which effectively prevents mold and most pest species.
Due to stricter regulations on pesticide use, Integrated Pest Management (IPM) has come into focus as an effective method in many museums and archives.
Depositories and custodial finds
Archaeological finds also need to be stored and cataloged; this is done in storage areas of archaeological collections and museums called depots. Similar to an archive, proper storage places certain demands on temperature, humidity, and lighting conditions in a depot, and the characteristics of the various objects must be weighed against each other. Proper labeling facilitates the identification and retrieval of individual pieces.
The term should not be confused with the term "depot find" in archaeology, which refers to objects or collections of objects that were once deliberately buried in the ground or sunk into a body of water or bog, i.e. deposited, in earlier times.
Inventory in archives and depots
Inventories are made to provide a better overview of the objects contained in an archive or depot. These inventories contain a systematic listing, often including a division into categories, the respective location, and the inventory number of each object. Additional information may include provenance, year of creation (if known), and the date the piece was added to the collection. In many cases, an inventory number is also assigned to each piece to truly identify it beyond a doubt.
Some inventories have existed for several hundred years; others, such as when a private collection is transferred to a museum holdings, must be newly created and systematized. In any case, it is advisable to update the categories regularly and to revise them if they become outdated (for example, when a large number of new objects are added, or when new scientific standards are introduced).
Inventory in relation to the protection and preservation of historical monuments
The process of systematic recording of monuments is also called "inventorying". It began in the 19th century and has not been definitively completed to this day, as new buildings continue to be added that meet the criteria to be classified as monuments. In the meantime, the inventory of all monuments comprises close to 600 volumes. The legal status of a building listed as a monument differs significantly from that of a building not listed as such, which is why the owner of a historical building can take legal action against its classification as a monument.
Digitization in archives
To ensure continued use, archival materials are also increasingly being digitized - on the one hand, to save irreparably damaged documents and the information they contain, at least in digital form, and on the other hand, to avoid unnecessarily burdening archival materials with physical use. A digital copy can be accessed as often as desired without risk to the original, which also enables more frequent use or use by a theoretically unlimited group of people. In addition, a steadily growing number of documents, such as electronic files, are now only produced digitally at all.