You can give a name such as foo to a cell or to any area of a sheet by selecting the cell or area then selecting Area Name... from the right mouse button menu. This will bring up the Area Name dialog box where you can enter any name you wish.

You can also name a cell or area by selecting it then typing the name into the small text box at the left end of the Formula toolbar, overwriting the cell reference that normally appears here.

If you enter a name that has already been used into this text box Calligra Sheets's selection will change to show the named cell(s).

The Data → Named Areas... option will give you a list of existing names and let you change Calligra Sheets's focus to any of them or let you remove a name.

Named cells are particularly useful in formulae as an alternative to absolute cell references as the names can be used in place of normal cell references and do not change when the cell containing the formula is copied. When a name is used in this way it should be enclosed in single quotation marks.

For example, if cell A1 has been given the name fred then you can enter a formula such as ='fred' + 2 into another cell which would always give the result of adding 2 to the value in A1 no matter where the formula cell was copied to.

Note that cell and area names are treated as being in lowercase.

A cell can contain a text comment that can be viewed when working on the spreadsheet but which is not printed and not normally seen.

To add a comment select the cell and choose Comment... from the right mouse button menu or from the Insert menu and type your comment into the resulting Cell Comment dialog box.

To see the comment hover the mouse pointer over the cell. The comment will appear as if it were a Tooltip.

If you check the Show comment indicator box of the Sheet Properties dialog, those cells containing comments will be highlighted by a small red triangle in the top right corner.

To open this dialog, click with the right mouse button onto the sheet tab at the bottom of the main window and select Sheet Properties from the popup menu. Or select it from the Format → Sheet menu.

To remove a comment from a cell, select Remove Comment from the right mouse button menu or choose Edit → Clear → Comment.