why db_host_instance => SQLEXPRESS in some config.php examples

[eugenepa]

I've looked at my own config.php for CE ver 6.0 and 6.15 and I don't see the line db_host_instance => SQLEXPRESS and I used mysql for the setup but in many places I see this but no real explanation as to why it's there when the database is mysql.

I see "SQLEXPRESS" and I think of Microsoft's SQL Server Express version and it's usage of instances but I've never thought of instances with mysql

In the copies of CE that I've installed I haven't seen this line -- why is that?

[al3]

I have the same question. What is this all about?