The task force drafting President Carter's tax-revision package has recommended that he consider proposing some further restrictions on the ability to wealthy persons to avoid payment of taxes through the use of tax shelters.

In position papers drafted for use in the final consideration of the tax package, Treasury officials call for modest limitations on the use of the real estate tax shelter - the major tax shelter not closed off by Congress last year.

They also propose a toughening of the so-called "minimum tax" - which is supposed to guarantee that at least some sheltered income will be taxed - and a reduction of the tax that can be offset by investment credits.

The proposals are among several recommended by Treasury in a Sept. 2 memorandum. It's not known yet whether Carter intends to follow the Treasury's advice in his final round of decisionmaking this week.

The Treasury documents also recommend liberalizing the retirement income credit for elderly persons, repealing the tax exemption voted last year for the tax exemption voted last year for the cost of prepaid legal services, and taxing some employee fringe benefits.

The proposals involving the tax shelters are certain to prove controversial. Congress was urged to pare back the real estate shelter in 1976, but heavy lobbying pressures left it unscathed despite closing of other preferences.

The tax shelter recommendations in the current Treasury proposal involve a series of changes:

The present deduction for depreciation on real estate would be trimmed somewhat. Treasury originally proposed limiting depreciation to the amount of equity a taxpayer has built up in an individual mortage or piece of property, but that recommendation reportedly has been softened substantially.

The minimum tax would be expanded to include deductions for intangible drilling costs in the list of taxable items. Today, they are included only to the extent that they exceed the income from oil-related properties.

Taxpayers would be prohibited from using the investment: tax credit to offset more than 90 per cent of their first $25,000 of tax liability. Today, there is no such rule. The limitation applies only to that above $25,000.

Last year's congressional crackdown limiting some shelter deductions to the amount an investor actually has "at risk" would be expanded to cover instances where a taxpayer is operating through a corporation or syndicate. (The provision would not apply to real estate shelters.)

The proposal affecting the retirement income credit would raise the maximum amount on which the credit is computed to $3,000 for single persons and $4,500 for couples - up from $2,500 and $3,750 under current law.

The retirement income credit was liberalized and expanded last year, but Treasury officials said a further break was justified to take account of higher social security benefit levels.

At the same time, the Treasury proposals would repeal the present retirement income credit for government employees. Treasury officials said the change was needed to reduce the advantage now enjoyed by federal employees.

Along with the tax shelter proposals, the Treasury position-paper also recommends toughening tax treatment of several currently-exempt employee fringe benefits, including business-lunch deductions and group life insurance.

The recommendations include:

Repealing entirely the tax exemption Congress voted last year for contributions and benefits received under prepaid group legal services plans. The break was expected to make legal services the coming new fringe benefit.

Denying business deductions for entertainment facilities, such as yachts, hunting lodges and club dues, and limiting deductions for business meals to 50 per cent of their actual cost.

Limiting the present tax exemption for income fron scholarships, fellowships and benefits under the GI bill to amounts spent on tuition and fees, and not compensation for living expenses, allowed under present law.

Treasury tax writers also rejected several proposals for taxing some government benefits that now are exempt, including social security and railroad retirement income, unemployment compensation and veterans and black lung payments.

They also rejected - for fear it would stir heavy industry lobbying - a potentially controversial plan to tax the interest built up on the portion of cash value life insurance or annuity contracts attributable to savings.

Treasury planners had estimated that provision, if passed, could bring in $1.1 billion in additional revenues. However, they warned, it could spur fierce opposition from the indusry.

The changes affecting the real estate tax shelter would mark a significant tightening of current law.

Along with the other proposals, the Treasury papers recommended these changes:

Phasing out, over 10 years, the present cost depletion for hard mineral properties (not gas and oil), which range from 22 per cent for sulphur to 5 per cent for oyster shells. The change would bring in $700 million in new revenues when fully effective.

Phasing out the present special deduction for mutual savings banks and savings and loan institutions which invest heavily in real estate, and for the first time taxing credit unions, which so far have been exempt.

The deduction for mutual savings banks and S&Ls would be reduced gradually from the present 40 per cent of net income to 20 per cent over a 5-year-period. The change will add $470 million to Treasury coffers.

Edging into the traditional tax-free status of state and municipal bonds by giving states and localities a choice of continuing to issue tax exmpt bonds or issuing taxable securities while receiving a subsidy to make up the difference in interest costs localities would have to pay.

For the first two years following enactment of such a proposal, the subsidy would amount to 35 per cent of the interest costs on these bonds. It then would rise to 40 per cent. The move would cap off a major "loophole" under which wealthy persons avoid payment of taxes.