It is possible to add notes and comments to requests. But after upgrading to Service Catalog 17.4.1 no formatting such as fat, font size or color are possible. This feature worked with the prevous release before the upgrade. The formatting can be done in the details, but the text just can't be stored at the request history then. Without any format information, the saving works fine.
Service Catalog v17.4 and up
In the Siteminder Agent configuration there is a parameter BadCssChars. By default this parameter is active but without content. In the referenced system it had been commented out.
Uncommented the BadCssChars parameter in the Siteminder Agent configuration.
More information about the BadCssChars parameter can be found here: Override the Default CSS Character Set