What is the ruling against China's South China Sea claims which India has backed?

The 2016 ruling issued by an international tribunal relates to a Philippines vs China case. The tribunal declared China's nine-dash line and land reclamation activities in the South China Sea "unlawful". The nine-dash line is a U-shaped line that appears on Chinese maps and marks the areas over which China asserts historical rights. India reaffirmed its backing for the ruling.