We are now using <span> elements to do some of the message formatting in fundraising banners, as this was agreed to be safe. A span with a single class works fine. However adding any more classes causes the span tag to be stripped out when the message is included in another banner.
For example:
- Source banner with 3 messages
- Destination banner including messages
- Displayed result - note the last message is not wrapped in any <span>
We can probably work around this if needed, but I don't see why multiple classes shouldn't be allowed.