I’m not sure if this is best classified as a bug or a feature request. For now, I put it under Bug reports, but if need be please move it.
It seems odd that you can create a new taxon when the same name already exists within the same hierarchy. This is becoming a larger issue as more and more subgenera etc get added.
For example this name exists under the subgenus Neoasciella under the genus Neoascia.
If I try and create the name Neoascia geniculata directly under the genus Neoascia, I am able to do it, despite it existing as a name in a child of the same genus. This just creates a duplicate of the same name under different parent.
I tried adding it via the manual page for curators, if you do it via the external lookups, it appears to recognize the name is already present and not create it, but the same logic does not appear applied to the manual taxa creation page.
Currently placed as a big report assuming the same functionality should be in place regardless of how you try to add a new name.