In 1949, Richard Greiner was sentenced to five years in prison for robbing a tavern in Baltimore. When he got out, he discovered his punishment wasn't over. He had trouble finding a job, could not obtain bonding when he tried to start a home repair business and was denied the right to vote.

Last year, Greiner did something about the prison record that had bedeviled him for 30 years. He obtained a pardon from Gov. Harry Hughes. It was a relatively simple process and for Greiner it lifted a tremendous burden. Yet it also left him with a lingering bitterness that for years a succession of lawyers and probation officials discouraged him from thinking he could ever clear his name.

"I had asked lawyers about clearing my record and they said it would take too much money and too much time," recalled Greiner, who said a pardon earlier in life would have helped him financially and emotionally. "Was I surprised to learn it just took a letter. No one ever told me until I started asking questions after Nixon got pardoned."

Greiner's experience was not unusual. In Maryland and most other states, the granting of pardons is an ill-defined and confusing area of corrections policy that many public officials do their best to ignore. The result is that thousands of ex-convicts who are eligible for pardons often don't even know they exist.

"It's not going to be made public knowledge that anyone can apply for a pardon," said Margaret Chippendale, who handles pardons for the Maryland Parole Commission. "We don't care to be bombarded with requests."

And they are not: In the last three years, only 32 persons have been awarded pardons in Maryland. During the same period, 38 were pardoned in Virginia. Officials in both states say the low rate has remained constant over the years. Pardons in the District of Columbia are handled by the U.S. Justice Department along with all other federal pardons, and no separate figures are available.

Many corrections experts view pardons as an important way in which former criminals can be brought back into society, and they are sharply critical of how they are usually handled. "It's distressing they're not used often enough," said Len Tropin, spokesman for the National Council on Crime and Delinquency, a nationwide research unit in Hackensack, N.J. "Not to use the pardon powers governors have is throwing away good tools for rehabilitation."

A historic power of governors and presidents, pardons traditionally are used to restore a convict's civil rights, such as voting, joining the armed services, serving on a jury, holding various professional licenses and being bonded. Technically, an offender's record is not cleared following a pardon, but those who have won pardons say they improve their chances for employment and ease the stigma of a criminal record.

For public officials wary of appearing too sympathetic to criminals, however, pardons often seem a no-win proposition. Granting a few pardons, along with commutations or early paroles, at Christmas or Easter, can be a symbol of a governor's good will at holiday time, but much more can be risky. As Brenda Pega, who screens pardons for Virginia, says of her own boss, "Gov. Dalton doesn't want to be a pardoning governor."

"Many people think pardons are a political handout and governors would just like to avoid them," said Noland Jones, director of the Criminal Justice Unit of the National Governors Association. Despite the benefits for certain ex-offenders, he said, pardons remain "politically infeasible."

As Greiner and others have discovered, the machinery for obtaining a pardon is shrouded in secrecy.

Parole and probation agents, who are aware of the program, rarely tell clients of their availability. "Our agents are not instructed to tell them anything about restoration of rights," said Alice Gustafson, a spokesman for the Maryland Board of Parole and Probation, who said a 1974 state law restoring voting rights to certain felons isn't discussed either. "If the question comes up, we tell them to go to their lawyers, because it's a legal matter."

But according to spokesmen for several governors, a lawyer is not required to obtain a pardon.

In Maryland, as in most states, the process begins with a simple letter to the governor, requesting a pardon. The state parole and probation office investigates the case, interviewing the applicants' friends, neighbors and employers. After the Maryland Parole Board votes to recommend a pardon, a two-sentence legal notice concerning the request is published once in a newspaper located in the county where the crime was committed. Maryland officials say few, if any, readers respond to the notices.

The governor is free to overrule the Parole Board's advice. If the pardon is granted, a letter is sent to the applicant and a record kept by the secretary of State. If the governor denies it, as Hughes has in 16 cases since 1979, no explanation is given.

Carl Eastwick, the Hughes aide who handles pardons, acknowledged there are "hundreds, if not thousands" of ex-offenders in Maryland who could be eligible. But most have no idea they qualify and so the number of applications is small.

Often lawyers and groups aiding ex-offenders have little understanding of the process. "We can't advise people about something we know so little about," said David Rothenberg, director of New York's Fortune Society, one of the nation's largest organizations aiding offenders. "Politicians don't want to assume the responsibility for awarding them, so it's a very clandestine thing."

Precise records on the number of applications for pardons are not kept. In Maryland, for example, between 40 and 70 requests are sent to the governor yearly from the Parole Commission, but no record is kept of those rejected initially for not meeting minimal eligibility. In Virginia, pardon requests are grouped with those seeking restoration of their voting rights, a number that has varied from 128 to 381 annually over the last five years. Applications for presidential pardons, including D.C. residents seeking clemency, average 300 a year.

Those who do apply become part of a process so informal that eligibility criteria are unwritten and change with each new occupant of the executive mansion. Even when the barest of guidelines exist, the governor can change them without notice, frustrating those trying to decide if they qualify.

Hughes did just that in July 1980, deciding that pardons would only be granted to those with five crime-free years after probation, regardless of the merits of a case. The former rule, still listed in the state code, is one crime-free year.

The Parole Commission, which describes the program to any ex-offenders resourceful enough to ask about pardons, did not learn of the change until it noticed a growing number of denials several months later.

Eastwick, the governor's aide, said the secrecy behind the new rule was inadvertent, but several ex-offenders whose pardons were denied because of the unwritten rule are bitter.

"I had to go through so much waiting just to get his on the governor's desk and then to find out about this rule," said Ed Teufel, 26, of Nutter Fort, W. Va., who was convicted of marijuana possession in Maryland in 1977. His lawyer, Ransom Davis of Baltimore, is even more critical. "The new policy surprised and angered us," he said. "It's not published and the commission said nothing about it. I was suspicious about the whole pardon policy then and now."

Raymond Lushbaugh, 32, of Hagerstown, released from prison nine years ago after serving a sentence for robbery, was also affected by the new rules. Although he has had a steady job and serves as a sergeant in his local fire department, he was on probation until three years ago.

As in Teufel's case, the Parole Commission had recommended Lushbaugh for a pardon, but Hughes denied the request in August. Until he was contacted by a reporter earlier this month, Lushbaugh was unaware of the decision.

"I've been waiting two years on this and I'm so disappointed," he said. "I have two children who don't know anything about my record. When I do tell them, it may be easier to break if there's a pardon.

"Now that I've figured out how to be eligible, I guess I'll just wait some more years," Lushbaugh said. "It would definitely help to have rules. I feel I have every service to the community he Hughes could want."

Exactly what the criteria are for receiving a pardon is difficult to ascertain, for Maryland, like most commissions, has no written policies on how it selects successful pardon candidates. Likewise, the reasons for granting pardons are as varied as the 50 governors.

In some states, all an applicant needs is a clean record and a stable home life. In others, like Virginia, "only those with exceptional achievements are considered," said Pega, who's screened pardon requests for the state for the last 11 years.

Contracting a terminal illness improves applicants' chances, she said, noting that several of the 13 pardons this year and 14 awarded in 1980 were for individuals dying of cancer.

The mystery surrounding the rarely granted pardons contributes to the frequent belief that they are expensive to win, or reserved for famous, white-collar criminals. The fact the nation's most notorious pardon was granted to an ex-president, Richard Nixon, colors this perception, as does the recent conviction of aides of former Tennessee governor Ray Blanton on charges of selling pardons.

"The people we work with think a pardon is for the upper middle class, applicable only to the wealthy," said Chuck Rousselle, director of the Offender Rehabilitation Program at the D.C. Public Defender's Office.

But in truth, the pardons are free. And, an examination of pardons granted in Maryland over the past three years shows most are ordinary citizens who committed a range of crimes, including robbery, assault, bigamy, shoplifting and sale of drugs.

Corrections officials acknowledge that many former convicts aren't suited for a pardon. Some are still involved in legal troubles, while others simply aren't interested. "There's a large segment so suspicious of the system they don't even bother," said Rothenberg, of the Fortune Society.

But for the ex-offenders who have led a clean life following prison, pardons can mean the difference in finding jobs, regaining a sense of worth and rejoining society, said Tropin, of the National Council on Crime and Delinquency.

For Greiner, a 59-year-old alcoholism counselor now living in Joppa, Md., the document has had a profound psychological effect.

The 1980 election, the first time Greiner was able to vote, was such an emotional experience that he remembers every detail, from how he pulled the booth curtain to what he and his wife ate at their celebration dinner afterward.

"He no longer has to be ashamed of his name," said his wife, Doris. "For the first time, it was like being free from something entangled around your neck."

The pardon "shaves off a guy's distrust of you," remarked Greiner. "It gave me a new outlook on life."