Table 1

Server Status Codes Server status codes are modeled after the familiar status codes of the HTTP 1.0 protocol.

Code
Meaning

200
OK, data follows
400
Bad command (command not recognized)
401
Bad data source (data source unknown)
402
Bad command arguments (arguments invalid)
403
Bad reference object (reference sequence unknown)
404
Bad stylesheet (requested stylesheet unknown)
405
Coordinate error (out of bounds/invalid)
500
Server error, not otherwise specified
501
Unimplemented feature

Dowell et al. BMC Bioinformatics 2001 2:7   doi:10.1186/1471-2105-2-7