>
>1 the current directory
>2 the TNS_ADMIN directory
>3 the /var/opt/oracle directory (Solaris) or /etc (all other Unixes)
>4 $ORACLE_HOME/network/admin

I agree with Brian, the TNS_ADMIN environment has priority. On Windows
the environment variable will take priority over a registry TNS_ADMIN
entry. I think only SQL*PLus will use tnsname.ora in the current
directory.

Daniel.