The unit fund tables that appear each week on page four of this section have undergone a makeover. The new format - fund tables are now classified under product provider rather than by product type - should be easier to follow.

This change brings the fund tables into line with European and US practice, and takes account of the increasing difficulty in classifying funds by product type in a more complex market.

Next to each fund name you will now see a two-letter category code, indicating the category the fund belongs to.

The code is, in general, easy enough to break, AE for American Equity, CA for cash, WP for with-profit and so on. A legend identifying the categories is provided on the page.

The introduction of gross roll-up - a new tax regime for unit funds and unit trusts - was the spur behind the change. Given the change in tax treatment, information on newer gross funds needs to be separated from older net domestic funds, which are still open.

The change to gross roll-up affects the timing and nature of taxation of the funds, since January 1st last.

Under the old set up, tax was deducted from funds every year at the standard rate of tax.

With the new gross roll-up system, the growth in the fund is taxed only once - at the point you withdraw the investment from the fund.

The rate of taxation is the standard rate of income tax plus 3 per cent (currently 23 per cent). The extra 3 per cent is supposed to compensate the Revenue Commissioners for the fact that they no longer receive the tax on an annual basis.

Gross roll-up is currently used in the US and throughout Europe, with the exception of Britain. Funds falling within this new regime are called "gross funds". Funds operating under the previous regime are now referred to as "net funds".

Performance data for net funds will show their gain/loss in the year to date and over a five-year period.

Gross funds, which have only emerged this year, will initially show year-to-date performance. Longer-term performance will appear as the new regime matures.

In the example shown, the Acorn Life deposit fund is now listed under Acorn Life. The category code is CA for cash.

Then the buy price and sell price are given in euros, followed by the year-to-date performance. The fifth column of information is the five-year performance figure. The rest of the cash funds are also listed under the heading of the financial institution providing them.

Caution is advised in interpreting the performance data as investment risk, investment policy and the structure of charges can differ between funds in the same category.

One of the long-standing rules of fund investment applies here and it's worth repeating - past performance is no guarantee of future returns.