Line numbers were optional in Zgrass, and typically only appeared on lines that were the target of a codice_7. Most BASIC interpreters required line numbers for every line of code, but this was due to their use in the "line editor"–if you needed to edit a particular line, the only way to refer to it was by number. Zgrass used a more advanced full-screen editor that eliminated this need. Zgrass allowed any string to act as a "line number", codice_8 and codice_9 were both valid. Zgrass also included nameless branches, using the codice_10 instruction, which would move forward or back a given number of lines.