[media-types] [IANA #1448324] image/vnd.sld registrati on request

Hi Darrel,

Sending a reminder for this request from March 24th.

thanks,
Amanda

On Tue Mar 24 23:17:58 2026, amanda.baber wrote:
> Hi Darrel,
> 
> Can you review this one by April 7th?
> 
> thanks,
> Amanda
> 
> =====
> 
> Name: Gareth Davidson
> 
> Email: [email protected]
> 
> Media type name: image
> 
> Media subtype name: vnd.sld
> 
> Required parameters: N/A
> 
> Optional parameters: N/A
> 
> Encoding considerations: binary
> 
> Security considerations: AutoCAD Slide files contain only static
> vector drawing commands (lines, filled polygons, and colour records)
> for rendering a viewport screenshot. The format does not contain
> active or executable content, does not support embedded objects or
> external references, and does not employ compression or container
> structures.
> 
> No privacy or integrity services are provided by the format. If such
> services are required, they should be provided externally, e.g.
> through the use of TLS.
> 
> Implementations should validate header fields (dimensions, aspect
> ratio) before allocating memory for rendering, as a malformed file
> could specify unreasonable dimensions.
> 
> Interoperability considerations: AutoCAD Slide files contain a byte-
> order test number at header offset 29. Readers must check whether this
> field reads as 0x1234 (same endianness) or 0x3412 (opposite
> endianness) and swap multi-byte values accordingly. Level 1 files
> (pre-AutoCAD Release 9) lack this field and are not portable across
> CPU architectures. Level 2 files (Release 9 and later) are portable
> when the test number is correctly handled.
> 
> The format has been stable since AutoCAD Release 9 (1987) with no
> known revisions.
> 
> Published specification:
> https://web.archive.org/web/20191223211310/http://www.autodesk.com/techpubs/autocad/acadr14/dxf/slide_file_format_al_u05_b.htm
> 
> Applications which use this media: AutoCAD (Autodesk, 1984-present)
> created and displayed slide files via the MSLIDE and VSLIDE commands.
> The netpbm toolkit provides conversion to portable bitmap formats via
> sldtoppm. The Pillow imaging library (via the pillow-netpbm plugin)
> provides read support in Python. The format is of interest to digital
> preservation projects for archival access to legacy CAD data.
> 
> Fragment identifier considerations: N/A - single static images with no
> addressable internal structure
> 
> Restrictions on usage: N/A - no restrictions
> 
> Provisional registration? (standards tree only): No
> 
> Additional information:
> 
> 1. Deprecated alias names for this type: application/sld,
> application/x-sld, image/x-sld
> 2. Magic number(s): AutoCAD\x20Slide\r\n\x1a\x00
> 3. File extension(s): sld
> 4. Macintosh file type code: N/A
> 5. Object Identifiers: N/A
> 
> General Comments: The unregistered types application/sld,
> application/x-sld, and image/x-sld appear in the PRONOM file format
> registry (x-fmt/105) and derived projects. This registration is
> intended to provide a canonical type to replace them. Note that
> application/sld may be confused with OGC Styled Layer Descriptor
> (application/vnd.ogc.sld+xml), which is a distinct XML-based format
> occasionally marked as application/x-sld.
> 
> Person to contact for further information:
> 
> 1. Name: Gareth Davidson
> 2. Email: [email protected]
> 
> Intended usage: LIMITED USE
> 
> Used only in older versions of AutoCAD, but it has not been replaced
> by a later format.
> 
> Author/Change controller: Autodesk, Inc. (registered on their behalf
> by Gareth Davidson)

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