When defining a JDBC driver as module and providing two versions as follows:

JBOSS_HOME/modules/com/microsoft/sqlserver/main/
JBOSS_HOME/modules/com/microsoft/sqlserver/2.0/

with according jar and module.xml

and defining the driver as follows in standalone.xml:

<driver name="mssql" module="com.microsoft.sqlserver" major-version="2" minor-version="0">
<xa-datasource-class>com.microsoft.sqlserver.jdbc.SQLServerXADataSource</xa-datasource-class>
</driver>

the following error is thrown:

15:53:32,805 ERROR [org.jboss.as.controller] (ServerService Thread Pool – 25) -> JBAS014612: Operation ("add") failed - address: ([
("subsystem" => "datasources"),
("jdbc-driver" => "mssql")
]): java.lang.IllegalStateException: JBAS010435: Specified driver version doesn't match with actual driver version

When debugging class JdbcDriverAdd, the slot main is always used.

I also tried to configure the driver as:

<driver name="mssql" module="com.microsoft.sqlserver" slot="2.0">
or
<driver name="mssql" module="com.microsoft.sqlserver:2.0">

but this does not work and is also not foreseen as from the scheme.

Also, there is no documentation of how to use major- and minor-version, only the following can be seen in the xsd:

Specifies the major/minor version of this driver. If the major and minor version is omitted the first available Driver in module will be used.