The following categories exist on the wiki, and may or may not be unused.Also seewanted categories.

• (Jacob) Tycho (Conrad) Vestergren taxa (3 members)
• -''colus'' suffix (2 members)
• -ii suffix (4 members)
• A (419 members)
• A-Fang Wu taxa (1 member)
• A-Yi Budian taxa (1 member)
• A-Young Kim taxa (2 members)
• A.-C. Nordenhed taxa (0 members)
• A.-E. Grobéty taxa (1 member)
• A.A. Haider taxa (1 member)
• A.A. Makarikov taxa (2 members)
• A.A. Saveliev taxa (0 members)
• A.A. Shodotova taxa (1 member)
• A.A. Thasun Amarasinghe taxa (34 members)
• A.B. Ahmad-Zaki taxa (0 members)
• A.B. Ivanovski taxa (0 members)
• A.B. Kolbe taxa (2 members)
• A.B. Meetei taxa (1 member)
• A.B. Pullen taxa (1 member)
• A.B. Stephenson taxa (1 member)
• A.C. Zeven taxa (1 member)
• A.D. Devjatilova taxa (0 members)
• A.D. El-Gamal taxa (1 member)
• A.D. Li taxa (1 member)
• A.D. Pawar taxa (3 members)
• A.E. Ergashev taxa (1 member)
• A.E. Shanavas Khan taxa (3 members)
• A.E. Sonnikova taxa (1 member)
• A.F.G. Slootweg taxa (1 member)
• A.F. van Oostrum taxa (2 members)
• A.G. Caljon taxa (1 member)
• A.H.E. Al-Musawi taxa (1 member)
• A.H. Haliday taxa (1 member)
• A.I. Filov taxa (0 members)
• A.I. Krotov taxa (1 member)
• A.I. Tsherepanov taxa (1 member)
• A.J.F.M. Dekker taxa (1 member)
• A.J.K. Griffiths taxa (1 member)
• A.J.L. Mitchell taxa (2 members)
• A.J.Ward Hornby taxa (2 members)
• A.J. Coquebert de Montbret taxa (1 member)
• A.J. Ivens taxa (0 members)
• A.J. Lynam taxa (1 member)
• A.J. Press taxa (1 member)
• A.J. da Silva Araujo taxa (1 member)
• A.J. de Boer taxa (0 members)
• A.K. Anusha Gayan taxa (1 member)
• A.K. Goel taxa (3 members)
• A.K. Gupta taxa (1 member)
• A.K. Jaiswar taxa (0 members)