server config, <VirtualHost>, <Anonymous>, <Global>, <Directory>, .ftpaccess
1.1.7 and later
PathAllowFilter allows the configuration of a regular expression that must be matched for all newly uploaded (stored) files. The regular expression is applied against the entire pathname specified by the client, so care must be taken when creating a proper regex. Paths that fail the regex match result in a "Forbidden filename" error being returned to the client. If the regular-expression argument contains whitespace, it must be enclosed in quotes.
# Only allow a-z 0-9 . - _ in file names, PathAllowFilter ^[a-z0-9._-]+$ # as above but with upper case characters as well PathAllowFilter ^[A-Za-z0-9._-]+$