ISO 11506:2009 specifies techniques for archiving electronic data to ensure their long-term integrity, accessibility, usability, readability and reliability, in order to protect the evidential value of the data.Long term is considered to be a period of time lasting more than a century (see ISO 5466).Black-and-white microforms processed with liquid chemicals are used in ISO 11506:2009 because the result is always an irreversible record and because of the proven quality of microforms as a long-term preservation media.ISO 11506:2009 also specifies procedures for the parallel recording, by a single production unit, of COM and COLD output from the same data.It applies to many different types of electronic data, such as text and two-dimensional graphic data which can be represented as a black-and-white image.