What does i:nil=“true” mean?

Question

I have an xml and it has nodes with i:nil=\"true\" in it. What does that mean?

For example:

Doe

Answer 1

nil is an attribute, defined in the i namespace. For this FirstName node, the attribute has the value true.

It's similar to this, just with different names and values:

...

Here, form is the name of the node, similar to FirstName from your code, and name is an attribute with a value of "test", similar to your attribute nil with a value of "true".

What this means depends on the application reading the xml document.

If I were to venture a guess, I'd say that this looks like part of a xml document defining some kind of schema, and that the FirstName field can have a NULL or nil value, meaning empty, or unknown.