mime-types-data

Description

mime-types-data provides a registry for information about MIME media type
definitions. It can be used with the Ruby mime-types library or other software
to determine defined filename extensions for MIME types, or to use filename
extensions to look up the likely MIME type definitions.

About MIME Media Types

MIME media types are used in MIME-compliant communications, as in e-mail or
HTTP traffic, to indicate the type of content which is transmitted. The
registry provided in mime-types-data contains detailed information about MIME
entities. There are many types defined by RFCs and vendors, so the list is long
but invariably; don’t hesitate to offer additional type definitions for
consideration. MIME type definitions found in mime-types are from RFCs, W3C
recommendations, the IANA Media Types registry, and user
contributions. It conforms to RFCs 2045 and 2231.

Data Formats Supported in this Registry

This registry contains the MIME media types in three formats:

  • A YAML format matching the Ruby mime-types library objects (MIME::Type). This is the primary user-editable format for developers. It is not shipped with the gem due to size considerations.
  • A JSON format converted from the YAML format. Prior to Ruby mime-types 3.0, this was the main consumption format and is still recommended for any implementation that does not wish to implement the columnar format, which has a significant implementation effort cost.
  • An encoded text format splitting the data for each MIME type across multiple files. This columnar data format reduces the minimal data load substantially, resulting in a performance improvement at the cost of more complex code for loading the data on-demand. This is the default format for Ruby mime-types 3.0.

mime-types-data Modified Semantic Versioning

mime-types-data uses a heavily modified Semantic Versioning scheme to
indicate that the data formats compatibility based on a SCHEMA version and
the date of the data update: SCHEMA.YEAR.MONTHDAY.

  1. If an incompatible data format change is made to any of the supported
    formts, SCHEMA will be incremented. The current SCHEMA is 3, supporting
    the YAML, JSON, and columnar formats required for Ruby mime-types 3.0.

  2. When the data is updated, the YEAR.MONTHDAY combination will be updated.
    An update on the last day of October 2015 would be written as 2015.1031,
    resulting in the full version of 3.2015.1031.

  3. If multiple versions of the data need to be released on the same day due to
    error, there will be an additional REVISION field incremented on the end
    of the version. Thus, if three revisions need to be published on October
    31st, 2015, the last release would be 3.2015.1031.2 (remember that the
    first release has an implied 0.)