The generic CSS link tag DITA2Go inserts in your HTML output looks like this:
<link rel="stylesheet" href="MyStyles.css" type="text/css">
Suppose you want to specify additional properties for the CSS file, such as media type. First, you must prevent DITA2Go from writing the generic link tag:
[CSS] WriteCssLink=No
To specify the link yourself, assign it to the <head> element:
[Inserts] ; You must type the following all on one line: Head=<link rel="stylesheet" href="MyStyles.css" type="text/css" media="screen">
As an alternative, you could reference the link as a macro (see §37.1 Defining and invoking macros):
[Inserts] Head=<$MyCSSLink>
[MyCSSLink] <link rel="stylesheet" href="MyStyles.css" type="text/css" media="screen">
You could even go a step further, and provide a macro variable (see §37.3 Using macro variables) for the value of the attribute, so you can change the value in just one place:
[MyCSSLink] <link rel="stylesheet" href="MyStyles.css" type="text/css" media="<$$MediaType>">
[MacroVariables] MediaType=screen