zanzibar: <sonia91> thank you very much for the clarification.
I think it's a bit difficult to keep up with all the conventions used throughout India - certainly it's more involved than I thought.
I originally assumed this article explained it all:
<He was named "Anand" at birth, and as a good South Indian Brahmin the name of his father was tagged on, to distinguish him from the hundreds of thousands of other Anands that walk the land. The system is simple: you get a name, one name, and add it to your father's name. This is similar to the Icelandic tradition, except the "son" part (as in Gustavson, Perutursson, etc.) is left out.>
As you can see, the qualification <good South Indian Brahmin> (as opposed to bad? - ha) is important, a nuance I missed.
The wiki article is very involved, almost dizzying. But I take it the relevant section is Maharashtra
<Family names in Maharashtra are most commonly derived from patronyms. However, town of origin and caste is also sometimes the source of family names.
In Maharashtra the most common format for names is: given name, father's name, last name. For example, for cricketer Sunil Manohar Gavaskar, "Sunil" is his given name, "Manohar" is his father's given name, and "Gavaskar" is his family name. The custom is similar among East Slavic people, many of whom also take a patronymic as their middle name.>
So, FIDE gives Sagar's name as <Sagar, Shah>.
Is <Shah> a patronym or surname?
And how are the names sorted, say, in a phone book? By given name or surname or patronym?