In reports etc rich text notes are sorted based on the complete content of the note, which includes the characters used to apply formatting. These formatting characters will sort above most other characters, and then causes sorted lists to appear in very odd orders negating the ease of use of that report.
My example of this is where I've used a rich text field to create a set of hyperlinks that lead to another more detailed report. Some of the products require header names which I format as bold but others don't. This results in what looks like a random alphabetical sortation which is confusing for the report recipients.
Aha engineering have confirmed that they don't provide a way to sort rich text fields based on the plain text content of the note so this idea is to request this feature.