VATICAN CITY -- The Vatican is leaning toward approval of an experimental application of the U.S. bishops' norms on clerical sex abuse, perhaps after some clarifying language is added, a senior Vatican official said.

"This would not be a rejection by the Vatican, nor would it be a formal 'recognitio' of the norms," the official said Sept. 23. Instead, the Vatican would allow the norms to be applied "ad experimentum" -- the Latin phrase signifying temporary or provisional use.

The official, who spoke on condition of anonymity, emphasized that a final decision had not yet been made, and the Vatican response had still not been written.

But he said the "prevailing sentiment" was to recognize that the norms were formulated by U.S. bishops as an experimental initiative -- to be evaluated after a two-year period. Therefore, the Vatican would respond with a conditional form of approval.

The solution, if adopted, appeared to represent a compromise. On one hand, U.S. bishops would be allowed to follow the norms they overwhelmingly approved in Dallas last June. On the other, the Vatican would not be officially recognizing the norms as a "particular law."

Many church legal experts at the Vatican and elsewhere have voiced criticism of the norms, saying they would not allow priests to effectively defend themselves from accusations. Among other things, the norms call for removing a priest from his church ministry when a "credible accusation" of sex abuse against a minor is received.

The delicate internal discussion on the norms, involving five Vatican agencies, was still continuing in late September. A draft of the final response was expected to be reviewed by Pope John Paul II in early October, Vatican sources said.

Sometime before the middle of October, the response -- probably in the form of a letter -- was expected to go out to the president of the U.S. Conference of Catholic Bishops, Bishop Wilton D. Gregory of Belleville, Ill., the sources said.

The senior Vatican official said it was possible that the Vatican might indicate some norms that need further study or wording changes before even conditional approval is granted.

In interviews in mid- and late September, informed Vatican sources said they considered the norms as well-intentioned but "imperfect."

They said the main problems with the norms as drafted were the unspecified time range for prosecuting such crimes, the unusual role of diocesan and national review boards, and ambiguity over the definition of some key terms -- such as "credible allegation" of sexual abuse.

On the other hand, some officials said, the Vatican appreciated that U.S. bishops had to act quickly and forcefully to confront the scandal of clerical sex abuse and rebuild the trust of the faithful. They said the Vatican did not want its response to appear as a "quashing" of the bishops' pastoral initiative or as a break with U.S. church leaders over the sex abuse scandal.

The issue was being handled in concert by Vatican agencies dealing with bishops, doctrine, the sacraments, clergy and church law. In late June, the agencies began requesting written input on the norms from a wide circle of experts.

Those interviewed by Catholic News Service spoke on condition of confidentiality, reflecting Vatican sensitivity on an issue that has caused the church great pain and damage.

They identified several areas where, in their view, the norms as written were incompatible with "universal law" or raised questions that need clarification:

-- The norms provide for a priest's permanent removal from ministry for any single act of sexual abuse against a minor -- "past, present or future." The Vatican sources said that in a legal sense this unlimited time frame would be unique, and in a pastoral sense it seems to go against the basic principle that a sinner can be redeemed.

Some Vatican officials said they were shocked to see U.S. priests removed from ministry on the basis of single episodes of sex abuse going back 30 or 40 years.

-- The norms call for establishment of diocesan and national review boards that are, in theory, consultative. But Vatican officials are bothered by some language that seems to suggest the bishops would be held accountable to these boards; they see that as an unacceptable infringement on the bishop's authority, or alternatively as an unacceptable delegation of his responsibility.

On a more practical level, Vatican officials are upset at the recent statements of Oklahoma Gov. Frank Keating, chairman of the bishops' National Review Board on sexual abuse. Among other things, Keating has pressured bishops to immediately implement the bishops' sex abuse policies and said he will release the names of those who do not.

In late July, Keating said that Catholics who find their bishop in flagrant violation of the new sex abuse policies should show their displeasure by withholding contributions and going to Mass in another diocese.

One Vatican official called Keating's statements "ridiculous" and another said his appointment to head the review board was a "huge, huge, huge mistake."

-- The norms make "credible allegation" the standard for relieving a priest of his ministry pending an investigation, but do not say who determines what is "credible."

In the eyes of some experts, this provision combined with language in the bishops' "Charter for the Protection of Children and Young People" implies that before a return to ministry an accused priest would have to prove the "credible allegation" was unfounded. They said this would reverse the standard legal principle by which a person is innocent until proven guilty.

-- The norms provide for bishops to request the dismissal from the priesthood of a priest-offender, even against his will. While acknowledging that this procedure has been used in a few particularly urgent cases in recent years, some Vatican experts questioned whether it should or could be written into a standard nationwide policy. They said it does not allow a defendant the same type of protection as foreseen in a judicial process.