Non-Catholics who want to teach in denominational schools were this week asked to subscribe to a 10-point, one-page charter if they want the Church's approval.
It hopes to introduce a revised system next session for new appointments but local authorities and unions remain cautious about the employment implications. They are demanding more details before they give their blessing.
Bishop Joe Devine, president of the Catholic Education Commission, on Tuesday launched a charter for Catholic schools at Turnbull High in Bishopbriggs, underlining its significance for all non-Catholics.
The Church says it holds no figures on the numbers of non-Catholic teachers but the bishops' version of the ten commandments emphasises that all staff appointed to a Catholic school are expected to "support and promote the aims, mission, values and ethos of the school", now defined by the charter.
Bishop Devine said: "The law requires that the bishops formally approve everyone who teaches in a Catholic school. There are now many non-Catholics who teach in Catholic secondary schools and this charter provides us with a way of giving approval, but not in terms of religious belief and character.
"If someone can sign up to this, they clearly stand for the values this document incorporates and that is sufficient for us to say that we would not oppose such a person being appointed. This is a document to which every teacher in a Catholic school should be able to subscribe to maintain the ethos and standards of education," he said.
The Church has to date approved Catholic teachers to work in Catholic schools but allowed non-Catholics entry with only the bare minimum assurances about their commitment. Recent employment discrimination legislation, however, has forced the Church to introduce an all-embracing system. Ironically, Catholic teachers could claim discrimination if non-Catholics were not approved.
But the approval system continues to raise concerns among members of the Educational Institute of Scotland. Non-Catholics claim they are largely excluded from senior posts and from curriculum areas such as religious and moral education or personal and social education where the Church feels that it needs Catholic teachers. The union has in the past been keen to test the system in court.
A Church spokesman said there was "no dubiety" about the charter's significance for non-Catholics. They would know precisely what the Church and its schools stood for and would have to sign up for that if they wanted to work in them. Recent European employment legislation had cleared the approval system as non-discriminatory, a point backed by the Department for Trade and Industry, the spokesman said.
Michael McGrath, director of the Scottish Catholic Education Service, said this was the first time there had been an explicit statement of the key features of Catholic education. "It people feel they could not commit themselves to the key aspects of the Catholic school, it would strike me as a bit odd they would want to work there," he said.
Mr McGrath, a former Cumbernauld secondary head, said it was about promoting a vision and countering the misunderstandings about Catholic schools, which were far more inclusive than many gave them credit for.
Around 20 per cent of all pupils in the 422 denominational schools are non-Catholics.
The director also said he had analysed inspectorate reports on 33 Catholic schools this year and all had shown high standards of pastoral care. "I think that is a tribute to our understanding of the human person, which is at the heart of Christian belief. Each person is deserving of the utmost dignity because they are made in the image and likeness of God and deserve to be treated with respect," he said.