SPField custom attributes in schema

I'm trying to decide whether it is possible to store custom attributes in a SPField's schema XML.

If you look at the .xsd for the 'Field' element in SharePoint, there are a slew of attributes. The last one in the attribute list is <xs:anyAttribute>. This elements purpose is to allow it be extended. This obviously leads me to believe it is possible to store custom attributes. However, I cannot find any documentation on this.

Anyone have any experience with this, or seen documentation saying yay or nay on the subject?

You are right you can have custom Attributes to the SPField,

<?xml version="1.0" encoding="utf-8" ?>
<FieldTypes>
  <FieldType>
    <Field Name="Property1">ConfigurableURL</Field>
    <Field Name="Property2">Value2</Field>
    <PropertySchema>
      <Fields>
        <Field Name="CustomAttributeOne" DisplayName="CustomAttributeOneDisplay" Type="Text"></Field>
      </Fields>
    </PropertySchema>
  </FieldType>
</FieldTypes>

You can find more information about the subject at the below links

Link1

Link2

Link3