For security reasons, do not file public and confidential documents together. This is further discussed in Section 4.3 below on the Security and Confidentiality of Information. The choice of the device or facility that assists in the retrieval of information is based on the method that is chosen for cataloguing. The most common forms of cataloguing are: • A card catalogue; • A list of catalogue entries; and • A computerized database. The most common way to store documents is to use folders. Folders may contain individual documents or sets of related documents. These documents may be organized in alphabetical order by author or source, or based on the geographical scope, the chronological order, or according to the nature, size or format of the document, or subject matter. Using a computer database to file information brings the advantages of not using as much space, providing a means of searching for information, data protection, and is easy to update. However, putting all the information into a computer database can be time-consuming, and it may not be suitable where there is no reliable access to electricity. 187 To maintain the storage and cataloguing system, assign notations that indicate their locations. Usually documents within the same folder are assigned numbers or notations that are numerically or alphabetically sequential. Years, months, names of sources or geographical terms can also be included in the notations. Documents can also be given unique record IDs. Documents may be grouped by events, with one event per folder. Standard formats can serve as the main contents of the folder, to which documents can be attached about the events such as fact-finding reports and testimonies. 188 4.2.4 Physical Information As discussed previously, it is a general rule to always leave a crime scene untouched. The handling of evidence normally requires professional forensic training in order to avoid contamination. When physical 187 International and CODESRIA, Ukweli. Monitoring and Documenting Human Rights Violations in Africa: A Handbook, 24 (2000), available at https://www.amnesty.nl/sites/default/files/public/ukw_eng.pdf. 188 Manuel Guzman and Bert Verstappen, What is Documentation?, HURIDOCS, 32 (2007), available at https://www.huridocs.org/resource/what-is-documentation/. 121