Description of XML configuration files.

Help me find documentation on XML configuration files describing the behavior of filters. What I found is not a complete description. There is a text

   <StringVectorProperty command="SetInputArrayToProcess"
                         element_types="0 0 0 0 2"
                         label="Input Array"

What values can parameters take? Is there a list of valid parameters? For example, there is this line

                         element_types="int int str int double double int str"

When to use what values? Sometimes string values are used, sometimes numeric.

Lots of goof info here:

Also this one about SetInputArrayToProcess