What is the variable in sfconfig.xml for solr home

[Jacob Singh]

I see in the docs:

System property substitution

Solr supports system property substitution, allowing the launching JVM
to specify string substitutions within either of Solr's configuration
files. The syntax ${property[:default value]}. Substitutions are valid
in any element or attribute text. Here's an example of allowing the
runtime to dictate the data directory:

   <dataDir>${solr.data.dir:./solr/data}</dataDir>


So what is the property for solr home?  I've tried solr.home,
solr.solr/home (from JNDI), solr.solrhome...

Thanks,
Jacob

P.S. is there a list of properties available somewhere?