– In 2018 and 2019, as part of the UK Legal Deposit Libraries’ sponsored ‘Emerging Formats’ project, the British Library’s digital preservation team undertook a program of research into the preservation of new forms of content. One of these content types was eBooks published as Mobile Apps. Research considered a relatively small number of apps in an attempt to better understand the preservation challenges associated with them and make recommendations for a way forwards. It found that whilst the content landscape is extremely varied, the technical challenges are similar for both Android and Apple apps. The greatest challenges appear to lie in the acquisition and access areas, particularly in enabling delivery to appropriate rendering environments and devices, though other challenges remain around the use of device sensors and content stored on remote servers rather than the user’s device. Whilst these challenges may be surmountable with sufficient resource and investment, the lack of growth in this content area in recent years makes large scale investment questionable.

This article introduces the British Library’s Flashback project, which is exploring the practical challenges of preserving digital content currently stored on physical media (magnetic and optical disks). It reports on a Flashback proof of concept that conducted experiments on a sample of content from hybrid collection items dating from between 1980 and 2000. It describes some of the activities undertaken by the proof-of-concept stage of the project from July 2015 to February 2016, including the initial collection profiling and sampling of content, the extraction of content from the disks, and the project team’s experiments with identifying and applying preservation approaches to the content, which included both emulation and migration. It concludes with some general observations on the approaches taken by the proof of concept and shares some recent findings from the second phase of the project, which is concerned with the practical challenges of developing an implementation strategy for the Library’s capture and preservation of digital content currently stored on physical media.

File format assessments have been the subject of much debate in and outside of the preservation community in the past decade. Recognizing the unique structural, operational, and collecting context of the British Library, the Library’s digital preservation team recently initiated new format assessment work to deliver recommendations on which file formats will best enable the preservation of integral, authentic representations of British Library collection content over the long term. This paper describes the work carried out to review previous assessments, identify appropriate sustainability categories and newly assess formats accordingly. We posit that the relatively ‘fuzzy’ nature of a file format requires a relatively open-ended assessment framework and a nuanced understanding of preservation risk that does not solely lie with ‘all-or-nothing’ format obsolescence. We review other work in this area and suggest that whilst previous format assessment work has addressed a range of subtly different aims, experience has since indicated that some of the criteria used such as considering number of pages in a format specification as a measure of complexity may be invalid. British Library assessments are made on documented points of principle, for example, an emphasis on evidence-based preservation risks and the avoidance of numerical scores leading to comparisons between formats, and these have formed the base upon which sustainability categories are defined. We present these categories, which help to identify preservation risks or other challenges in the management of digital collections, and provide an overview of initial assessments of three formats: TIFF, JP2, and PDF. We acknowledge however, that implementation of preservation requirements, e.g., the use of particular preservation-justified file formats, must be balanced against other business requirements, such as storage costs and access needs, and argue that transparency of this format assessment process is fundamental if the resulting recommendations are to be fully understood in the future.