In the Admin UI, setting the Keystone 'nav' headings to pre-set title values auto-assigns an icon (Octicons) to the heading (source: https://github.com/keystonejs/keystone/blob/master/admin/client/App/screens/Home/utils/getRelatedIconClass.js) based on the title.
The titles that are considered "recognized" are very presumptuous and not very broad; it would be more useful to include the ability to specify an icon inside the same 'nav' definition as the models, which would be passed directly to
this.props.icon
(source: https://github.com/keystonejs/keystone/blob/master/admin/client/App/screens/Home/components/Section.js#L6)
Example:
keystone.set('nav', {
'small animals': {
icon: 'octicon octicon-squirrel',
lists: ['mice', 'rats']
}
});