At an overflowing railway station on a recent Friday night in Soweto, black police stalked through the crowd that was rusing go get home. Stopping disembarking passengers at random, the police were checking for the little brown book, waving on those who had them, hauling off those who did not.

The 36-page, passport-size plastic document is the book of life for South African blacks. It is the document that shows that an African has received government permission to leave the poor tribal reserves to work at better-paying jobs in the "white" cities - a piece of identication coveted by the thousands of blacks who are waiting in the reserve hoping to make the move.

But the passbook as it is officially known, is also the biggest and longeststanding single grievance of all generations of blacks in South Africa. As early as 1919, African National Congress leader S.M. Magatho labeled the document "a badge of slavery."

The controversy surrounding the pass book has become so hot recently that the government last week announced its intention to reform the "pass laws." But the question now is whether reform will be enough. Many Africans are calling for complete scrapping of the little brown book and the many laws behind it.

Officially, the pass book is part of the "influx control" laws designed to prevent an overflow of blacks from the nine tribal reserves, or homelands, to the cities, which can only provide a limited number of jobs for African laborers.

In practice, however, the laws empower the government to tell blacks where they can live and work, what areas they can visit and for what period of time, and with whom they can associate.

Passbooks register everything from tax payments to monthly verification from whites that blacks are still in their employ.

The influx control laws have been among the most effective means of dividing the races. Their impact was reflected in a story told by a white social worker who often visits the tribal homelands.

On one occasion recently she took her young daughter along to the homelands when a babysitter could bot be found. When they arrived at a school in the reserve, children peered from the window and then came pouring out of the school to surround the mother and child.

When a frantic black teacher finally got the children back in the classroom, the social worker asked what had upset the students.

"Oh, they weren't upset at all," the teacher explained. "It's just that they had never seen a white child. Your daughter fascinated them.

Last week, the government appointed Viljoe Commission on Penal Reform blasted the influx control measures as a "continuing source of conflict."

Relieving police of enforcement of petty pass laws and curfew regulations would allow time for investigation of serious crime, the report pointed out, adding that pass-law convictions are the main reason for over population of South African prisons.

The Viljoen Commission recommended that if pass laws were deemed unavoidable, then the government should at least give serious consideration to removing penal sanctions so that violators - those not carrying a pass book either because they had forgotten the document or had never received one - were not sent to jail, but subject instead to "administrative or regulatory controls."

Liberal member of Parliament Helen Suzman hailed the Commission as "one of the few signs of enlightenment." The liberal Johannesburg newspaper, the Rand Daily Mail, editorialized:

"The government's own commission has had the perception to pinpoint some of the harm these laws are doing, unpalatable though that may be to traditional Nationalist (the ruling party) ideology."

The Mail also pointed out: "What remains to be seen is whether the government will have the courage to face up to the upleasant truths."

Minister of Bantu (black) Administration M.C. Botha reacted with an announcement that three leaders of tribal reserves and government officials were conducting a joint investigation reserves and government officials were conducting a joint investigation into the possibility the pass laws.

Minister of Justice James Kruger then said that his department accepted the recommendation that violators be sent to rehabilitation centers rather than prisons, and that compulsory sentences should be abolished.

But in a speech to Parliament Friday, Prime Minister John Voster indicated that his government would not consider abolishment of the pass laws, and claimed that African leaders accepted the need for influx control.

Some blacks are already expressing concern that the few recommendations accepted or under consideration could, in the long term, be manipulated so that they become even more punitive for Africans struggling to stay in the white areas.

A black journalist pointed out that the proposed rehabilitation centers could end up in the tribal reserves, thus providing the government with an additional means of forcing blacks back to the homelands.

The government's pledge to abolish definite terms, instead of promising to lighten sentences, could lead to even longer detentions for some than sentences now stipulated, he said.

The government has given no indication that it will use the recommendations in this way. But the journalist's concerns reveal the depth of distrust and suspicion among blacks about government "concessions."

Vorster's indication that the will never support abolishment of the pass laws, however, is certain to make the issue even more volatile. As an African teacher in Soweto commented: "Most blacks would relax if pass laws were abolished. It would be taken as a sign that government does really intend to answer black grievances.

"Pass laws are really the major obstacle, the ultimate humiliation to blacks," the teacher said, "even to those like my parents who aren't political. They don't care about power-sharing, but they do get angry about having to carry passbooks around with them at all times, keeping them stamped every month and showing them to police all the time."

Blacks argue that goverment commissions as far back as 1942 called for repeal of pass laws. In 1942 the Smit Commission condemned the laws outright: "The harrassing and constant interference with the freedom of movement of natives gives rise to a burning sense of grievance and injustice."

The Fagan Commission of 1946-48 warned: "During the travels of our commission through the country it was brought to our notice in an unmistakable manner that the feeling amongst the natives against the pass laws is a very violent one."

At neither point did the government accept the recommendations, and Africans are seriously concerned that not even six months of growing racial tensions will convince the current government of the need to repeal the measures.

As a moderate white pointed out: "The government realizes it has to respond to black demands and it knows that the pass laws are a major complaint.

"But to do that would be to give the Africans a type of freedom and a recognition of their place outside the homelands that goes against everything this government stands for."