This image is part of the biochemical reaction arrow series. The series was created for what is now the Metabolic Pathways task force of the English Wikipedia's WikiProject Molecular and Cell Biology. Files in it are named systematically. The system is as follows:
File:Biochem reaction arrow Y XXXX Z med.svg
Y is a word indicating the chemical direction of the arrow, either "forward", "reverse", or "reversible".
XXXX is a list of four characters indicating whether each side has an arrow or not. Each X is replaced with "Y" or "N" to indicate the presence or absence of a side arrow. The first letter indicates the top left; the rest follow clockwise.
Z: is a word indicating the graphical orientation of the arrow, either "horiz" or "vert".
Most images possible in the above scheme do not exist. However, you can usually create them by rotation and reflection of an existing image. GKFXtalk is happy to carry this out if needed.