There is no such thing in either the Latin Church or any of the Eastern Churches, not even in the Orthodox and Anglican communities.
Once you leave the community, you are no longer bound to obey the rules and superiors of the community.
In addition, Canon Law says that religious communities, secular orders, societies of apostolic life, and secular institutes make public profession of vows or promises, whichever case applies. The Church receives them. How can the Church receive a promise or a vow from a community that is a secret?
Whether you’re in a religious order, congregation, secular order or society of apostolic life, at your profession there must be the following, besides you:
a. the major superior who receives the profession in the name of the community
b. an ordained minister (deacon, priest or bishop) who receives the profession in the name of the Church. He need not be a member of the community.
c. two witnesses
The profession is recorded, just like baptism and marriage. There are no secrets.
In countries and times when it is dangerous for religious to “out” themselves, such as those countries that are anti-Catholic or anti-cleric, the community may exist underground. But the profession still requires that the same people witness it and that it be recorded. Otherwise, how will you find your way around the Church when you come out of hiding?
It the poster is talking to us about his FORMER community, then I doubt that it’s underground. Common sense would dictate that you do not go on the internet and advertise. If it’s your former community, you’re no longer bond to that community by obedience.
I’m not going to push the OP for the name of the community; however, I warn people, any community that tells you not to reveal who they are raises red flags.
Fraternally,
Br. JR, OSF