Employees of most federal regulatory agencies will be happy to learn that they are, in fact, allowed by statute to accept Christmas gifts from members of their own families.

But, that's about it.

New or redefined rules concerning gifts, entertainment and general ethics are taking hold in most agencies, and with the holiday season, many agency heads have decided to remind their employees of the need to avoid the "appearance of conflict of interest."

Two the chagrin of other agencies, the Interstate Commerce Commission last week issued one of the strongest statements about gifts and entertainment.

"I am concerned about . . . contact between commission personnel and those we regulate or deal with officially," ICC chairman Dan O'Neil told his employees in a written statement. "Acceptance of entertainment or gifts by commission personnel from such individuals or groups could leave the wrong impression with the public about our relationship with these parties."

O'Neal put some bark in his bite by promising not to "attend holiday parties sponsored by regulated carriers, shippers, practitioners or other such groups. As chairman of this agency, I advise all commission employees to follow the same practice."

Other agencies have, or will soon, issue warnings to employees to avoid the possibility of conflicts during the holidays.

At the newly-created Department of Energy, a recent statement from Secretary James Schlesinger was particularly strong.

Urging DOE employees to set an example for others to follow, Schlesinger told his staff:

"Even seemingly trivial courtesies can present the appearance of impropriety and must be avoided. For example, gifts such as floral arrangements offered to the secretary or personal staff of a DOE official should not be accepted."

At the Civil Aeronautics Board, the final rules on employee conduct and responsbilities were issued two weeks ago. Fortunately for Christmas revelers, they don't take effect until Jan. 3.

In the new rules, employees are told not to solicit or accept gifts or entertainment "from any organization or person having an interest before the board." That group has been expanded to include newsmen and representatives of trade associations.

In what appears to be the only actual value limit stipulated in regulatory agency regulations. CAB employees have been told to return, or turn over to the CAB's Ethics Counselor, any gift with an intrinsie value in excess of $1.

Employees at the CAB are also forbidden from accepting invitations to social functions unless the board pays the host for the employee's participation. Exceptions are made when the employee is the speaker, or a formal participant, or when a civic groups is the host.

Earlier this year the Food and Drug Administration issued a call for new guidelines because of what is called "perceived problems of undue industry influence on regulatory decisions."

The guidelines finally were released in September, and mostly correspond with those of other agencies.

"The acceptance of food and refreshments of nominal value on infrequent occasions in the ordinary course of a luncheon or dinner meeting or other meeting . . ." is acceptable at the FDA.

At the Federal Maritime Commission the rules against accepting certain gratuities and entertainment are much the same as other agencies, with some interesting exceptions.

FMC employees are allowed to participate in "keel layings, christenings and ship launchings, and accept meals, accommodations and entertainment related thereto when the invitation to such an event is addressed to the commisssion, and the chairman of the commission approves the acceptance of the invitation."

At the Securities and Exchange Commission, employees are warned not to "engage in criminal, infamous, dishonest, immoral, or notoriously disgraceful conduct, or other conduct prejudicial to the government."

Internal Revenue Service employees can accept certain items through their employee organizations, if those items have been "disbursed for ordinary advertising and public relations purposes, and which are made available to attract employees as customers, rather than in regard to their status with Internal Revenue Service."

Federal Communication Commission employees are told that they cannot give gifts to superiors, and that no employee can "accept a gift from an employee receiving less pay than himself."

At the small business Administration, that rule has been amended to forbid accepting gifts from employees of "less rank."

The Commodity Futures Trading Commission will put out its annual warning on Friday, according to a spokesman. He said it will state basically "that this is the season to be jolly, but don't be jolly with somebody else's money."

At the Federal Deposit Insurance Corp, examiners and assistant examiners "shall not accept a loan or gratuity from any bank examined by him or any bank he has the authority to examine or from any person connected therewith."

Consumer Product Safety Commission personnel are allowed to accept such things as short-distance transportation if it is "furnished in connection with the performance of the employee's official duties when other transportation is not otherwise available or convenient."

Federal Trade Commission are told that they may make or accept "a voluntary gift of nominal value or donation in a nominal amount on a special occasion such as marriage, illness or retirement."

Several agencies have similer exceptions.

Says one agency spokesman, "We are pretty loose about attending after hours' parties held by the industry, but we really get in a bind if one of our employees wins a door prize."