No you don't understand.

It's not secret at all.  It's discreet, and it encourages one never to live on a name or a banner.  But instead to develop one's understanding of Church teaching so deeply and competently that one doesn't need to "stand on a banner" for living as faithful Catholic people.

In some countries living one's Catholic faith is quite dangerous...not only in Spain during their Civil war, but in Cuba and in China today.  One can die.

Where one receives additional formation in order to pursue holiness isn't anyone's business..and that's why Opus Dei doesnt' publish list of people who are members.

If a member themselves wants to tell others where they receive spiritual help, it's entirely in their personal freedom to do so.

But again, one doesn't stand behind a banner.  One must study and learn the teachings of the Church that no banner is needed. 

You don't understand the difference.

John Allen wrote a book on this and presented the same points as I am here doing.