Uncle Sam’s long-standing policy of giving veterans a hiring preference for government jobs enjoys strong support.

But it’s a pain to explain.

The preference is so complicated, confusing and difficult to understand that it tempts abuse.

That’s the takeaway from a Merit Systems Protection Board (MSPB) report released this week. Congress should consider “creating a simpler system,” MSPB suggested.

“It’s a mess,” said Ted Daywalt, president of VetJobs, an online jobs board sponsored by the Veterans of Foreign Wars. He’s concerned that too many vets don’t get the preference they are due. “It needs to be reworked.”

MSPB’s study comes three months after another by the Partnership for Public Service, which reported on federal personnel executives who think that, in certain circumstances, the preference “can result in the exclusion of all nonveterans without regard to their relative qualifications.”

While the veterans’ hiring preference is perplexing, perhaps sometimes frustrating, it also is popular with Congress.

“The laws regarding veterans’ preference in federal hiring may be complex, but they were written with a noble purpose — to give those who have served their country a justified preference for federal civilian employment,”said Rep. Elijah E. Cummings (Md.), the top Democrat on the House Oversight and Government Reform Committee.

Senate Veterans’ Affairs Committee Chairman Bernie Sanders (I-Vermont) said he strongly supports veterans’ hiring preferences not just because vets have “put their lives on the line, but just the basic reality that when you are away and not in the civilian labor market for a period of years, you fall behind people your age in a very competitive economy.”

Yet the popularity of the preference does not put it beyond controversy.

An MSPB survey said 6.5 percent of respondents reported inappropriate favoritism towards veterans and 4.5 percent reported a denial of veterans’ preference rights.

Neither figure is large, but each can have negative ramifications. In a letter introducing the report, Susan Tsui Grundmann, the MSPB chairwoman, said, “The survey data showed that employees are less likely to be engaged and more likely to want to leave their agencies if they report having observed either of these two types of conduct.”

Negative perceptions are higher in the Defense Department, where 8 percent of the employees surveyed reported “inappropriate favoritism towards veterans.”

MSPB wrote about staffer allegations that Defense Department “job descriptions were being written specifically for retiring members of the armed forces, that the retired military were being hired by their friends without regard for which applicant was best qualified, and that there was a repeated pattern of a person being in the work unit as an active military service member on a Friday and reporting as a civilian the following Monday — timing that appeared very suspicious to the respondents and implied that the job had been held for the military retiree.”

Perceptions that hiring managers write job descriptions “for their retiring friends (or even for themselves as their own retirement approaches) have led to the term ‘no Colonel left behind’ being added to the Federal HR lexicon,” the report continued.

Rep. Darrell Issa (R-Calif.), chairman of the House committee, recalled his panel’s probe into a “startling example” of abuse in a related veterans’ preference program: “A contractor who never served a day in the military received a veterans’ preference due to an injury suffered in a military prep school.”

But isolated examples like that don't diminish what Issa called the “bipartisan priority” of looking after veterans.

Nathan Christensen, a Pentagon spokesman, said the MSPB report “provides an opportunity for the Department to reinforce hiring officials’ responsibilities within the laws and regulations, and to further educate the workforce about the rules regarding veterans’ hiring.”

In contrast, the Office of Personnel Management (OPM) got defensive. In a letter included with the report, Mark Reinhold, an OPM associate director, told MSPB that “OPM does not concur in your somewhat negative assessment.” Reinhold added that MSPB “seems really to be taking aim at the entire civil service system in its current form.”

I read the report and don’t understand how OPM came to that conclusion.

But some rules MSPB noted make no sense.

Mothers of veterans are eligible for hiring preference, but not fathers and not all mothers. A mother is eligible if she is or was married to the veteran’s father. Apparently, unmarried mothers need not apply. And the regulations don’t know what to do with same-sex parents.

“We asked OPM why it had concluded that the woman’s spouse must be the father of the veteran,” MSPB said, “and OPM indicated that the question required further study.”

There are a number of veterans’s preference issues that need further study, but the preference, in one form or another, is here to stay.

A simpler form, however, would be nice.

Twitter: @JoeDavidsonWP

Previous columns by Joe Davidson are available at wapo.st/JoeDavidson.