When asking about gender in forms, it's usual to find designers who narrowed the options to female and male, omitting non-binary identities, but a frequent alternative is including a third “Other” option, where all “other genders” are acknowledged but marginalized1Geoffrey C. Bowker and Susan Leigh Star, “Enacting silence: Residual categories as a challenge for ethics, information systems, and communication”, Ethics and Information Technology, no. 9 (2007): 273–280..
Othering
A sought resource is classified in a parent residual category.