404. That’s an error.

The requested URL /translate_c?depth=1&hl=ro&prev=search&rurl=translate.google.com&sl=en&sp=nmt4&u=https://en.wikibooks.org/wiki/Chess_Opening_Theory&xid=17259,15700019,15700124,15700186,15700191,15700201,15700248&usg=ALkJrhihmyDNvhisbFwT_Iu8QpDElGX8eA was not found on this server. That’s all we know.