Using FT8 with Special Event Call Sign

[kj4lpi]

How do I work the world cup special event station HP18FWC on FT8 ?
The call sign appears to have too many characters. Adding one space and my six character call sign makes 14, which is one too many.

[K5CKS]

I had the same problem today. Very perplexing. I saw ZW29B/AUER on 15M FT-8. FT-8 said he was in India. I figured he was operating portable Arab United Emirate Republic. Boy was I wrong :-) He is in Brazil at the Bauerfest; a celebration of the Germans who immigrated to Brazil. FT-8 didn't like his call no matter what I tried. When I clicked on his call FT-8 refused to populate the Standard Messages. I finally manually put his call in and then Generated Standard Messages. That kinda worked, I was able to put out a call to him and he answered with a +7. I tried to send him a signal report but FT-8 would only send a + or -... no numbers. This doesn't make sense because his call was only 5 characters. I think the FT-8 programmers are going to have to figure this out otherwise "special event" calls are not welcomed on FT-8 which would be very sad.
73!
Rory, K5CKS

[4L5A]

Yes Rory, ZW29BAUER is in Brazil