Middle club symbol. what is it?

In Wyps numeric there is a club symbol in the middle. Why? What rule has changed?

I saw it this morning on my mobile, I thought it is a problem with the new design on the mobile, but when I checked on the PC now, I found it there. It seems to be a wild card, but why Richard did not announce the change of the rules?

Another change of rules, the count of tiles is fixed for all numbers, not as before. Richard, can you confirm this change of rules?

Well, it is a wild card as I expected, and it works exactly like asterisk in GWG.