Standard Delay Format
This page describes one of several data formats known as SDF, in this case the Standard Delay Format file. It is a "textual file format for representing the delay and timing information of electronic systems". It has been approved as an IEEE standard P1497 in December 2001. A pre-approval version is available at http://www.eda.org/sdf/sdf_1497_draft_0.10.pdf.
The format is referenced in the Wikipedia stub page on Standard Delay Format.
A Standard Delay Format file contains its own version number as part of its header, see below.
The file format can be created, read and manipulated with many different software packages..
Each Standard Delay Format file is a text file that starts with a header, starting with the string (DELAYFILE . The header next has a strong defining the version, eg (SDFVERSION "4.0"). Version 4.0 is the earliest version defined by the IEEE standard.
There is no specific naming convention for Standard Delay Format files, but more usually the file extention .sdf is used. Apparently .sdo for Standard Delay Format Output File can also be used. The MIME Type is not known.
A pre-approval specification is available at http://www.eda.org/sdf/sdf_1497_draft_0.10.pdf.