relnote(116): SVG q unit supported (defined in CSS length units)

files/en-us/mozilla/firefox/releases/116/index.md

@@ -31,6 +31,8 @@ This article provides information about the changes in Firefox 116 that affect d
 
 ### SVG
 
+- The [`q`](/en-US/docs/Web/SVG/Content_type#length) length unit (`1q = 1/40th of 1cm`) is now supported ([Firefox bug 1836995](https://bugzil.la/1836995)).
+
 #### Removals
 
 ### HTTP

files/en-us/web/svg/content_type/index.md

@@ -186,34 +186,33 @@ SVG makes use of a number of data types. This article lists these types along wi
 
     SVG supports two types of _IRI_ references:
 
-    - **local _IRI_ references**, where the IRI reference does not contain an `<absoluteIRI>` or `<relativeIRI>` and thus only contains a fragment identifier (i.e., `#<elementID>` or `#xpointer(id<elementID>)`).
-    - **non-local _IRI_ references**, where the _IRI_ reference does contain an `<absoluteIRI>` or `<relativeIRI>`.
+    - **local _IRI_ references**, where the IRI reference does not contain an \<absoluteIRI> or \<relativeIRI> and thus only contains a fragment identifier (i.e., `#<elementID>` or `#xpointer(id<elementID>)`).
+    - **non-local _IRI_ references**, where the _IRI_ reference does contain an \<absoluteIRI> or \<relativeIRI>.
 
       For the full specification of IRI references in SVG, see [SVG 1.1 (2nd Edition): IRI references](https://www.w3.org/TR/SVG/linking.html#IRIReference).
 
 ## Length
 
 - \<length>
 
-  - : A length is a distance measurement, given as a number along with a unit. Lengths are specified in one of two ways. When used in a stylesheet, a \<length> is defined as follows:
+  - : A length is a distance measurement, given as a number along with a unit.
+    SVG follows the [CSS Values and Units Module](https://www.w3.org/TR/css-values-3/) for the definitions of common units and their meanings.
+    For example:
 
     ```plain
-    length ::= number (~"em" | ~"ex" | ~"px" | ~"in" | ~"cm" | ~"mm" | ~"pt" | ~"pc")?
+    length ::= <number> (<absolute-length> | <relative-length>)?
     ```
 
-    [See the CSS2 specification](https://www.w3.org/TR/2008/REC-CSS2-20080411/syndata.html#length-units) for the meanings of the unit identifiers.
+    For more details, see the CSS specification for [Relative length units](https://drafts.csswg.org/css-values/#relative-lengths) and [Absolute length units](https://drafts.csswg.org/css-values/#absolute-lengths) and the [\<length>](/en-US/docs/Web/CSS/length) CSS data type.
 
-    For properties defined in CSS2, a length unit identifier must be provided. For length values in SVG-specific properties and their corresponding presentation attributes, the length unit identifier is optional. If not provided, the length value represents a distance in the current user coordinate system. In presentation attributes for all properties, whether defined in SVG1.1 or in CSS2, the length identifier, if specified, must be in lower case.
+    For properties defined in CSS Values and Units, a length unit identifier must be provided.
 
-    When lengths are used in an SVG attribute, a \<length> is instead defined as follows:
+    For properties that are SVG-specific and their corresponding presentation attributes, the length unit identifiers in length values are optional. If not provided, the length value represents a distance in the current user coordinate system. In presentation attributes for all properties, whether defined in SVG or in CSS, the length identifier, if specified, must be in lower case.
 
-    ```plain
-    length ::= number ("em" | "ex" | "px" | "in" | "cm" | "mm" | "pt" | "pc" | "%")?
-    ```
-
-    The unit identifiers in such \<length> values must be in lower case.
+    When used in an SVG attribute, the unit identifiers in length values must be in lower case.
 
-    Note that the non-property \<length> definition also allows a percentage unit identifier. The meaning of a percentage length value depends on the attribute for which the percentage length value has been specified. Two common cases are:
+    Note that the non-property \<length> definition also allows a percentage (`%`) unit identifier.
+    The meaning of a percentage length value depends on the attribute for which the percentage length value has been specified. Two common cases are:
 
     - when a percentage length value represents a percentage of the viewport width or height
     - when a percentage length value represents a percentage of the bounding box width or height on a given object.