Have you ever been typing in a list of items in Excel and suddenly found Excel has started automatically filling in formulas in one of the columns or copying the formatting down to each new item in the list? Have you wondered why this happens sometimes but apparently not all the time?
The first thing you need to do is to check one of the Excel options. Go to the Tools, Options screen and select the Edit tab, see whether the ‘Extend list formats and formulas’ option is selected. Here are the screens first for Excel 2007, and below that previous versions:
For the automatic extend to work, this option must be turned on, and a rather long list of other conditions has to be satisfied. Perhaps the two most significant are:
At least three of the previous five rows must feature the formatting or contain the formula that is to be extended; and
A formula to be extended must not contain a range name (anyone know why?)
There is a far more complete description of how the option works, together with a list of situations in which it won’t work on the Microsoft site:
http://support.microsoft.com/kb/231002
