Font Variation Description

A way to unambiguously, compactly and clearly describe a set of @font-face properties. This is implemented as a simple string. For example.

n4

With these two characters we can choose a font, or generate style and weight information for an @font-face rule.

font-style: normal;
font-weight: normal;

Properties

The order of properties is well defined. Currently:

font-style
font-weight

Forward compatibility is maintained by adding new properties to the end. Possible additions:

font-stretch
font-variant

Values

The possible values for each property are well defined, and a value is required for each property. Values must be a single character. The Font Variation Description value and its equivalent CSS value for each property are as follows.

Each property must have a default value, but may have aliases for use when generating a Font Variation Description. To maintain unambiguous output, there must be no alias return values.

font-style

n: normal  (default)
i: italic
o: oblique

font-weight

1: 100
2: 200
3: 300
4: 400 (default, also recognized as 'normal')
5: 500
6: 600
7: 700 (also recognized as 'bold')
8: 800
9: 900

font-stretch

a: ultra-condensed
b: extra-condensed
c: condensed
d: semi-condensed
n: normal          (default)
e: semi-expanded
f: expanded
g: extra-expanded
h: ultra-expanded

font-variant (not currently in the CSS3 font spec)

n: normal
c: small-caps

Parsing Rules

See compaction test suite, expansion test suite and parser test suite for a complete set of rules.

Examples:

(no properties)
=> n4

font-style: italic;
=> i4

font-weight: normal;
=> n4

font-weight: bold;
=> n7

font-style: normal;
font-weight: 400;
=> n4

font-style: italic;
font-weight: 500;
=> i5

A CSS class name for a single font

wf-droidserif-n7

Describing an entire family of fonts. Here each variation is delimited by a comma.

"Droid Serif:n4,i4,n7,i7"

This string describes four fonts in the family 'Droid Serif':
- Normal
- Italic
- Bold
- Bold Italic

Copyright and License

Copyright (c) 2010 Adobe Systems Incorporated.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.