FTP Reply Codes
FTP 501 — Syntax error in parameters or arguments
In FTP Reply Codes, code 501. The official source describes it as “Syntax error in parameters or arguments”. Its concrete cause depends on the operation and surrounding message.
Code501
Symbol—
Source confidencehigh
Official definition
Syntax error in parameters or arguments
In plain language
In FTP Reply Codes, code 501. The official source describes it as “Syntax error in parameters or arguments”. Its concrete cause depends on the operation and surrounding message.
Context to inspect
- The surrounding operation, version and subsystem determine the actual cause.
- The same numeric value can mean something different in another namespace.
Safe first checks
- Confirm which product, protocol or subsystem produced the code.
- Read the full surrounding error message and inspect relevant logs.
- Compare the code with the linked authoritative documentation before changing configuration.
Important context
The surrounding operation, version and subsystem determine the actual cause.