As respostas de erro de cache são possíveis com a palavra-chave always
:
add_header Cache-Control "public; max-age=3600" always;
Adds the specified field to a response header provided that the response code equals 200, 201 (1.3.10), 204, 206, 301, 302, 303, 304, 307 (1.1.16, 1.0.13), or 308 (1.13.0) ... If the
always
parameter is specified (1.7.5), the header field will be added regardless of the response code.