CSS -o- vendor extensions support in Opera Presto 2.7

The CSS specification allows for vendor-specific extensions. These are usually (but not exclusively) used for experimental additions to the CSS specification that have not yet reached Candidate Recommendation stage. The -o- prefix extension identifies an Opera experimental property or keyword.

Opera recommends that the final declaration of the property should be added to your style sheet if you use the unprefixed version. That way, future versions of the browser that include the feature after it becomes fully standardized can easily apply the style. See the following example.

-o-transform: scale(1.6);
transform: scale(1.6);

For further reference, please see our Opera Developer Network blog article written by Bruce Lawson. Please note that each vendor extended property is hyperlinked to its place in various CSS modules.

Opera -o- vendor extensions

Property	CSS module reference	Support
-o-border-image	CSS3 Backgrounds and Borders Module Note: Opera only supports the border-image shorthand property with the use of the -o- prefix.	Yes
-o-object-fit	CSS3 Image Values and Replaced Content Module Note: Originally "image-fit", renamed to "object-fit".	Yes
-o-object-position	CSS3 Image Values and Replaced Content Module Note: Originally "image-position", renamed to "object-position".	Yes
-o-tab-size	CSS3 Text Module	Yes
-o-table-baseline	MathML for CSS Profile	Yes
-o-transform	CSS3 2D Transforms Module	Yes
-o-transform-origin	CSS3 2D Transforms Module	Yes
-o-transition	CSS3 Transitions Module	Partial
-o-transition-delay	CSS3 Transitions Module	Partial
-o-transition-duration	CSS3 Transitions Module	Partial
-o-transition-property	CSS3 Transitions Module	Partial
-o-transition-timing-function	CSS3 Transitions Module	Partial