* Tighten up the definition of "numeric ID" in Flickr URLs, so only something that could plausibly be a numeric ID is allowed.
e.g. `https://www.flickr.com/photos/circled/\xE2\x91\xA0\xE2\x91\xA1\xE2\x91\xA2\x60\x20\x77\x69\x6C\x6C\x20\x6E\x6F\x20\x6C\x6F\x6E\x67\x65\x72\x20\x62\x65\x20\x72\x65\x74\x75\x72\x6E\x65\x64\x20\x61\x73\x20\x61\x20\x70\x6C\x61\x75\x73\x69\x62\x6C\x65\x20\x70\x68\x6F\x74\x6F\x20\x55\x52\x4C\x2E\x0A\x0A\x23\x23\x20\x76\x31\x2E\x31\x2E\x30\x20\x2D\x20\x32\x30\x32\x33\x2D\x31\x30\x2D\x31\x38\x0A\x0A\x2A\x20\x20\x20\x41\x64\x64\x20\x74\x68\x65\x20\x61\x62\x69\x6C\x69\x74\x79\x20\x74\x6F\x20\x72\x75\x6E\x20\x66\x6C\x69\x63\x6B\x72\x5F\x75\x72\x6C\x5F\x70\x61\x72\x73\x65\x72\x20\x66\x72\x6F\x6D\x20\x74\x68\x65\x20\x63\x6F\x6D\x6D\x61\x6E\x64\x20\x6C\x69\x6E\x65\x2E\x0A\x2A\x20\x20\x20\x52\x65\x6D\x6F\x76\x65\x20\x73\x6F\x6D\x65\x20\x75\x6E\x6E\x65\x63\x65\x73\x73\x61\x72\x79\x20\x64\x65\x70\x65\x6E\x64\x65\x6E\x63\x69\x65\x73\x20\x66\x72\x6F\x6D\x20\x60\x73\x65\x74\x75\x70\x2E\x70\x79\x60\x2E\x0A\x0A\x23\x23\x20\x76\x31\x2E\x30\x2E\x30\x20\x2D\x20\x32\x30\x32\x33\x2D\x31\x30\x2D\x31\x37\x0A\x0A\x49\x6E\x69\x74\x69\x61\x6C\x20\x72\x65\x6C\x65\x61\x73\x65\x20\x6F\x66\x20\x74\x68\x69\x73\x20\x63\x6F\x64\x65\x20\x61\x73\x20\x61\x20\x73\x74\x61\x6E\x64\x61\x6C\x6F\x6E\x65\x20\x6C\x69\x62\x72\x61\x72\x79\x2E\x0A