Although billed as an undramatic, middle-of-the-road document, President Carter's multi-billion-dollar budget has some very interesting stuff for his 2.7 million staffers.

Examples:

Federal and military personnel would "lose about $2.9 billion in pay raises due them this October. Instead of using the current "comparability" system that would guarantee them a 10.9 percent pay catchup with industry, Carter wants Congress to approve pay reform that will produce a more "realistic" 6.2 percent federal pay raise.

Military personnel under pay reform no longer would get the same percentage increase as civilians. Their October boost would be 7.4 percent, according to Carter's budget.

The number of full-time federal workers would drop about 1,300 during the upcoming fiscal year, but some agencies and departments will get more people.

Carter made no mention of proposals to merge the civil service retirement program with social security. The idea -- which sends cold chills up the backs of federal workers and retirees -- is being kicked around in Congress.The politically explosive concept apparently will get no nudge from the White House this year.

New legislation will go to Congress shortly to tighten up federal compensation programs that Carter says have been abused. There has been a lot of publicity recently on federal workers who get job-related injury benefits while they are competing in Olympic try-outs or running karate studios.

More work now being performed by federal employes will be contracted out. Defense expects to cut more than 1,000 jobs that way, but experts believe the total number of federal positions taken over by contractors will be much, much higher.

The price of the federal civilian payroll (excluding the giant U. S. Postal Service) will go to $54.9 billion if the president gets pay "reform" and the 6.2 percetn raise goes into effect.

The budget claims that the government will "recover" about $20 million this year by charging workers to park, and that figure will jump to $40 million in 1982 when employes are required to pay full commercial rates for parking at the office.

Government agencies will be required to buy or lease cars that get 24 miles per gallon. Since that is a "fleet average" figure, however, it will still permit VIPs to use larger gas-guzzlers than do the other ranks.

Defense is planning to take action to realign, consolidate or close military bases that would produce an annual savings of $125 million. Such actions have, since 1977, eliminated 24,000 civilian military position and saved $375 million a year.

Federal job-hunters can see where the action is -- and is not -- by looking at these budget empolyment projections. The numbers represent the increase, or decrease, in jobs from 1980 to 1981:

Agriculture down 100 jobs to 85,000 . . . Commerce, up 400 to 31,200 . . . Defense, down 1,000 to 913,000 . . . Education, down 100 to 6,000 . . . Energy, steady at 20,300 . . . Health and Human Services (HEW without the E) down 2,100 to 138,000 . . . Interior, up 200 to 55,300 . . . Justice, down 300 (mostly in the FBI) to 55,400 . . . Labor, down 300 to 22,700 . . . State, up 100 to 22,000 . . . Transportation, up 500 to 72,200 . . . Environmental Protection Agency, up 200 to 11,200. . . Space Agency, up 100 to 22,700 and Veterans Administration, a decrease of 1,100 to 200,800.

Other major federal agency job changes projected include AID, stable at 5,753 . . . GSA, up 200 . . . Nuclear Regulatory Agency, up 300, Office of Personnel Management steady at 6,600.