The Federal Election Commission is in the midst of a heavy spring housecleaning of its election code.

It already has gotten Hill approval of regulation changes that could bring rock and country/ western back into presidential politics. It has before Congress changes that would make federal campaigns safe for skywriters. A third set, in the draft stage, could relieve the pangs of conscience of John B. Anderson.

Some explanations:

Benefit concerts for presidential primary candidates fell out of favor in 1980, when the FEC altered the rules to permit matching funds only for that portion of the ticket price above fair market value. Now the FEC has gone back to the original system used in 1976, giving a match for the full ticket price.

A cumbersome new procedure requires the signature of a concert-goer on a form indicating that the proceeds are going to a candidate, but Democratic presidential campaign staffers say they think it can be handled, and are seeking musical talent.

As for the skywriters, Congress now has before it a new regulation making it clear that if a candidate hires a plane to write "Doe for Congress" across the skies he needn't have it also emblazon the disclaimer "Paid for by the Doe for Congress Committee" in the clouds.

The new regulations say such disclaimers have to be placed on yard signs and posters, but not in places that are "impractical."

The skywriting exemption was triggered by a complaint in a New Jersey congressional race against a candidate who had his name written out in huge letters on a 100-foot-high water tower, but put the standard disclaimer notice on a typewritten page on one of the tower legs. The FEC said doing otherwise would have been impractical.

And as for Anderson, the commission has before it a draft rewrite of the rules that would for the first time permit federal campaign financing to qualified "independent" presidential candidates as well as to major party and third-party candidates.

The FEC ruled in 1980 that Anderson qualified for matching funds because his National Unity Campaign was the "functional equivalent of a party." Anderson has said he is considering running again next year, but he insists he is a genuine independent and doesn't want to go through the ruse of running as a third-party candidate.

ENTREPRENEURIAL SPAT . . . The heightened public interest in campaign finance has produced a cottage industry of new publications detailing who gave how much to whom, and the FEC is being asked to referee a tiff among competitors over what may be reprinted from FEC reports.

It has received a complaint from David U. Greevy, president of PAC Researchers Inc. of Burke, Va., against William Smith, president of Contributions Inc. of Washington, for publishing a source book that lists, among other things, the names of all individual contributors to winning congressional candidates in 1981-82.

Greevy points out that the election code prohibits the sale or use of the FEC's list of individual contributors for commercial purposes.

Smith said the prohibition is designed to protect a contributor's privacy, and that he honored its intention by not including addresses alongside names. The matter is before the FEC.

BARE BONES . . . . Commission Vice Chairman Lee Ann Elliott has told a congressional subcommittee that the FEC's fiscal 1984 budget request of $10.3 million is, when adjusted for inflation, the third smallest request in the agency's eight-year history.

If the budget is approved the FEC will go into the presidential year with a staff of 245, compared with the 271 it had in 1980.

The proposed budget does provide for the agency to hire back eight of the 16 audit positions eliminated in a reduction in force last year. The commission is also working out an agreement with the General Accounting Office to borrow some auditors during the peak candidate-reporting times in 1984.