You may notice on Membership web forms that Additional Members name fields display as required. There is an asterisk next to the Last Name field for every member, not just the first.
These fields aren't actually required, and the Membership form will function properly, even if you don't fill in the name fields for additional members. If a patron does decide to enter in an additional member they would then be required to enter the last name since Altru must have at least a last name when entering new constituents.
Steps to Duplicate
Go to Memberships.
Choose a membership program, and then go to the Terms and Levels tab.
Find a level that allows for more than 1 member.
Go to Web>Manage Membership Forms
Find the Membership level we found in step 3. Click the green arrows next to this level.
Make sure this form is activated for the website, and then click the URL.
See that the second member requires the last name. Don't fill this in.
Submit the form with only the first member filled out. See that it goes through.