Hi Ed,
Checklists with no players pictured (or not team specific - like 1981 Fleer had 2 distinct teams on each checklist) should be designated as "No Team".
To list a card with 2 or more teams, select "Multiple Teams". On the next screen displayed, there will be a text box where you will need to type in the team names (careful with the spelling) in this format (minus the quotes):
"Philadelphia Phillies / Detroit Tigers"
Then, if on the main card page, there are no teams linked, you'll also have to link the teams by clicking the link to "edit team links". On that page, edit the links so that the teams are selected and update and "return to card".
If you have any specific examples of cards you worked with and aren't sure if they are correct, send me a private message and I'll be glad to take a look.
-- Dan --
Note: Please see my profile for more info regarding trading (section updated 3/4/2024). I have added a large portion of my inventory to the site, and currently have trading turned on (details are in my profile).