503 Service UNAVİLABLE

It is a sign that means "temporarily closed" on web pages. It is mostly used for maintenance or during transfer on the web page.

503 header codes for php

Header (`http/1.1 503 Service temporarily unavilable`); > Header (`retry-exterior: 300`); // 300 Seconds

503 header codes for asp

& lt;%

response.status = "503 Service Unavailble"
Response.Cachecontrol = "No-Cache" Response.Addheader "Pragma", "No -Cache"
Response.expires = -1

%& gt;