What is the Doc Type for tiles 2.2

Question

I have used tiles 2.0 with this Doc type:

<!DOCTYPE tiles-definitions PUBLIC
"-//Apache Software Foundation//DTD Tiles Configuration 2.0//EN"
"http://tiles.apache.org/dtds/tiles-config_2_0.dtd">

but now I want to try some things of tiles 2.2 if I don't know if the correct Doc type is:

A -

<!DOCTYPE tiles-definitions PUBLIC
"-//Apache Software Foundation//DTD Tiles Configuration 2.1//EN"
"http://tiles.apache.org/dtds/tiles-config_2_1.dtd">

B-

<!DOCTYPE tiles-definitions PUBLIC
"-//Apache Software Foundation//DTD Tiles Configuration 2.2//EN"
"http://tiles.apache.org/dtds/tiles-config_2_2.dtd">

I ask this because on the Tiless 2.2 Documentation put that the corrects are:

1 -

<!DOCTYPE tiles-definitions PUBLIC
"-//Apache Software Foundation//DTD Tiles Configuration 2.0//EN"
"http://tiles.apache.org/dtds/tiles-config_2_0.dtd">

2-

<!DOCTYPE tiles-definitions PUBLIC
"-//Apache Software Foundation//DTD Tiles Configuration 2.1//EN"
"http://tiles.apache.org/dtds/tiles-config_2_1.dtd">

Can anyone tell me which can I use?

Thanks !!!