4 Basic Data Types and Color Keywords

4.1 Basic Data Types

The common data types for SVG's properties and attributes fall into the following categories:

<Boolean>: A <Boolean> is specified as either 'true' or 'false', and is therefore a subset of XML Schema Part 2 xs:boolean types in that it does not accept '0' or '1' as valid values.
<integer>: An <integer> is specified as an optional sign character ('+' or '-') followed by one or more digits "0" to "9". If the sign character is not present, the number is non-negative.

Conforming SVG Tiny 1.2 content must use <integer> values with a range of -32,768 to 32,767.
<number> (real number value): A real number value is specified in either decimal notation or in scientific notation. A <decimal-number> consists of either an <integer>, or an optional sign character followed by zero or more digits followed by a dot (.) followed by one or more digits. A <scientific-number> consists of a <decimal-number> immediately followed by the letter "e" or "E" immediately followed by an <integer>.

Conforming SVG Tiny 1.2 content must use <number> with the capacity for a fixed point number in the range '-32,767.9999 to +32,767.9999'. It is recommended that higher precision floating point storage and computation be performed on operations such as coordinate system transformations to provide the best possible precision and to prevent round-off errors.
<length>: A length is a distance measurement. The format of a <length> is a <number> optionally followed immediately by a unit identifier. If the <length> is expressed as a value without a unit identifier (e.g., 48), then the <length> represents a distance in the current user coordinate system.

SVG Tiny 1.2 only supports CSS units on the the 'width' and 'height' attributes on the 'svg' element. These can specify values in any of the following CSS units: in, cm, mm, pt, pc, px and %. If one of the unit identifiers is provided (e.g., 12mm), then the <length> is processed according to the description in Units.

Percentage values (e.g., 10%) on the width and height attributes of the svg element represent a percent of the viewport (refer to the section that discusses Units in general).
<coordinate>: A <coordinate> represents a <length> in the user coordinate system that is the given distance from the origin of the user coordinate system along the relevant axis (the x-axis for X coordinates, the y-axis for Y coordinates).
<list of xxx> (where xxx represents a value of some type): A list consists of a separated sequence of values. Unless explicitly described differently, lists can be either comma-separated, with optional white space before or after the comma, or white space-separated.

White space in lists is defined as one or more of the following consecutive characters: "space" (U+0020), "tab" (U+0009), "line feed" (U+000A) and "carriage return" (U+000D)

Here is a description of the grammar for a <list of xxx>:
```
ListOfXXX:
    XXX
    | XXX comma-wsp ListOfXXX
comma-wsp:
    (wsp+ comma? wsp*) | (comma wsp*)
comma:
    ","
wsp:
    (#x20 | #x9 | #xD | #xA)
```
where XXX represents a particular type of value.
<color>: The basic type <color> defines a color within the sRGB color space [sRGB]. <color> applies to SVG's use of the 'color' property and is a component of the definitions of properties 'fill', 'stroke', viewport-fill', 'stop-color' and 'solid-color'.

SVG supports all of the syntax alternatives for <color> defined in Syntax for color values. All RGB colors are specified in the sRGB color space (see [SRGB]). Using sRGB provides an unambiguous and objectively measurable definition of the color, which can be related to international standards [COLORIMETRY].
<paint> : The values for properties 'fill' and 'stroke' are specifications of the type of paint to use when filling or stroking a given graphics element. The available options and syntax for <paint> are described in Specifying paint.
<transform-list> : The detailed description of the possible values for a <transform-list> are detailed in Modifying the User Coordinate System: the transform attribute.
<iri> The <iri> type holds a reference to an International Resource Identifier (see IRI): An IRI is the address of a resource on the Web. For the specification of IRI references in SVG, see IRI references.
<Clock-value> : The detailed description of the possible values for a <Clock-value> are detailed in Animation: Clock values.
<xslt-qname>: As xslt-qname is a QName occuring in attribute content as defined in the XSLT 1.0 Recommendation whereby if it has a prefix, then the prefix is expanded into an IRI reference using the namespace declarations in effect where the name occurs, and the default namespace is not used for unprefixed names.
<languageID>: A languageID is the set of valid language identifiers as defined by the xs:language data type in XML Schema Part 2, plus the empty string.
<Focus> : The detailed description of the possible values for a <Focus> are detailed in Specifying navigation.
<ContentType> : a media type, as per [RFC2045].
<FontFamilyValue> : a font family as detailed in Font selection properties.
<FontSizeValue> : a font size as detailed in Font selection properties.
<FormatList> : a list of format specifiers as detailed in The requiredFormats attribute.
<ID> : an XML ID.
<PathData> : path data as detailed in the Paths chapter.
<Points> : a list of points as detailed in the Basic Shapes chapter.