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Digital Repository: Preservation & Format Support Policy


Format Support

To assist content creators in creating, converting and depositing documents that meet the level of quality necessary for full information capture and the highest degree of preservability over time, the CSU-Pueblo Digital Repository (hereafter "CSUPDR") is developing a set of specification and format best-practice guidelines for common content types. NOTE: It is important to refer to the Registered Formats and Support Levels Table when deciding on what format to use. For example, the table clearly shows that a PDF-A document is given the highest level of preservation support versus a Word document.

The CSU-Pueblo Library is committed to providing long-term access to the digital works the repository contains by adhering to digital preservation best practices. However, the level of preservation support provided for a contribution is determined by the file format in which it is submitted. Software, hardware, and file format obsolescence is a complex issue with outcomes that are difficult to predict. This includes the future ability to of the Library to convert obsolete file formats to accessible file formats without any loss to an original document’s look and feel. The CSUPDR will initially provide three levels of preservation support for specific file formats at the outset, as follows:

Greatest Preservation Support (Level 1)

The CSUPDR will provide its highest level of preservation support, making its best effort to maintain the content, structure and functionality in the future. Level 1 service level is currently provided only for formats that are both publicly documented and widely used. This provides a high degree of confidence in our preservation commitment because it is more likely that tools will exist or be developed to undertake preservation actions, and that those actions will result in an understood and controlled transformation or migration.

Note: The content may be normalized (transformed to another stable format) to provide additional assurance that the information content is preserved or to facilitate discovery and viewing.

Limited Preservation Support (Level 2)

The CSUPDR will make limited efforts to maintain the usability of the file. The format will be monitored and may be transformed when significant risk to access is imminent but it is likely to be difficult to predict or control the consequences of any transformation or migration on content, structure or functionality.

Note: The file may be transformed to a more preservable format to ensure that the information content is not lost, even if some structure and functionality are sacrificed.

Minimal Preservation Support (Level 3)

The CSUPDR provides basic preservation of the file (bitstream) and associated metadata as-is with no active effort made to monitor the format and associated risks or to normalize, transform or migrate the file to a more preservable format. Files may be opened and/or read by future applications, but there is no guarantee that the content, structure, or functionality will be preserved.

Note: Any format not yet reviewed and evaluated by the CSUDR team will receive level 3 service on deposit. A higher level may be assigned after format review takes place.

Three Levels of Preservation Support

Preservation Level

Level 1

Level 2

Level 3

Persistent identifier that will always point to the object and/or its metadata

Provenance records and other preservation metadata to support accessibility and management over time

Secure storage and backup

Periodic refreshment to new storage media

Fixity checks using proven checksum methods

Storage in a trusted preservable format (making a normalized version, if necessary)

for some formats

 

Strategic monitoring of format

 

Migration to succeeding format upon obsolescence

 

 

The three levels of preservation commitment are made at the individual file level. Complex content items comprised of multiple files in various formats will need additional evaluation to determine whether the operational relationships between the files can be maintained. If the original relationships are documented externally in metadata, that information will be preserved in any case. In addition, executables and some files that rely on a specific hardware/software environment will require additional evaluation because not only the format but the access environment must be considered in making a preservation determination.

Registered Formats and Support Levels

The following list of formats and support levels will be reviewed and updated based on our growing experience with digital preservation and the emergence of new formats and standards. If you have a format that isn't listed below, please contact Karen Pardue by email at karen.pardue@colostate-pueblo.edu or by phone at (719) 549-2326 for more information.

Text, Page Description, and Microsoft Office File Formats

Format

File Extension

Mime Type

Support Level

Qualifying Factors/Notes

PDF/A*

.pdf

application/pdf

Level 1

Files not created per the “Best Practices” receive Level 2 support, and may be migrated to PDF/A

Plain Text
UTF-8
(Unicode)

.txt

text/plain;
charset=UTF-8

Level 1

 

Plain Text
ANSI
X3.4/ECMA-6/US ASCII (7-bit)

.txt

text/plain;
charset=US-ASCII

Level 1

 

Postscript

.ps

Application/ps

Level 2

 

Rich Text

.rtf

Text/richtext

Level 1

 

XML

.xml

text/xml

Level 2

Deposit of appropriate DTD/schema with XML file is strongly encouraged and may impact preservation. Minimally, XML should be well-formed; explicit namespaces strongly preferred.
Assumes no DTD/schema but that XML file is well formed.

HTML

.html, .htm

text/html

Level 3

Requires HTML 4.0 or 4.01 validated markup and CSS files(s), if referenced, must be deposited with document.

*PDF/A is preferred over PDF whenever possible, as it is becoming recognized as the archival standard. See http://en.wikipedia.org/wiki/PDF/a for more information.

 

Format

File Extension Mime Type Support Level Qualifying Factors/Notes
         

LaTeX

.latex

application/x-latex

Level 2

We encourage that content should be converted to PDF/A by the depositor.

TeX

.tex

application/x-tex

Level 2

We encourage that content should be converted to PDF/A by the depositor.

Microsoft Word

.doc
.docx

application/msword

Level 2

We recommend that content be converted to PDF/A by the depositor.
Requires that macros be disabled.

Microsoft PowerPoint

.ppt
.pptx

application/vnd.ms-powerpoint

Level 2

We recommend that content be converted to PDF/A by the depositor.
Requires that macros, animations and other effects be disabled.

Microsoft Excel

.xls
.xlsx

application/vnd.ms-excel

Level 2

We recommend that content be converted to PDF/A by the depositor.
Requires that macros be disabled.

 

Image File Formats

Format

File Extension

Mime Type

Support Level

Qualifying Factors/Notes

TIFF

.tiff

image/tiff

Level 1

This format is often slow to load unless compressed into a lossless format such as JPEG 2000

JPEG 2000

 .jp2

image/jp2

Level 1

Preferred over JPEG

JPEG

.jpg

image/jpeg

Level 1

JPEG 2000 preferred.

PNG

.png

image/png

Level 2

 

BMP

.bmp

image/x-ms-bmp

Level 3

 

GIF

.gif

image/gif

Level 3

 

 

Audio File Formats

Format

File Extension

Mime Type

Support Level

Qualifying Factors/Notes

Wave

.wav

audio/x-wav or audio/wav

Level 2

 

MPEG audio

.mp3

audio/mpeg, audio/mp3

Level 2

 

AAC_M4A

m4a, .mp4

audio/m4a, audio/mp4

Level 3

 

AIFF

.aif, .aiff

audio/aiff, +

Level 3

.wav or .mp3 preferred

Audio/Basic

.au, .snd

audio/basic

Level 3

.wav or .mp3 preferred

Windows Media Audio

.wma

audio/x-ms-wma

Level 3

.wav or .mp3 preferred

 

Video File Formats

Format

File Extension

Mime Type

Support Level

Qualifying Factors/Notes

MPEG-4

.mp4

video/mp4

Level 2

Many variants possible; preservation level not yet established

AVI

.avi

video/avi, video/msvideo, video/x-msvideo +

Level 3

.mp4 preferred

Quicktime

.mov

video/quicktime, video/x-quicktime

Level 3

.mp4 preferred

MPEG-1
MPEG-2

.mp1
.mp2

video/mpeg
video/mpeg2

Level 3

Many variants possible; preservation level not yet established
.mp4 preferred

Windows Media Video

.wmv

video/x-ms-wmv

Level 3

.mp4 preferred

What to do if your format is not listed

Please contact Karen Pardue by email at karen.pardue@colostate-pueblo.edu or by phone at (719) 549-2326 if you have questions about a particular format.

Used with permission from CSU Libraries Digital Repository page