Except the current value of a [variable](invantive-composition-variabele-waarde), you can also use a deviated value. For a header and/or footer it is even impossible to meaningfully use a variable value. You got to choose a group value. The following group values are possible for a variable `$V{naam}`:
- `first`: the first value in the series of the variable. Empty if there is no initial value.
- `last`: the last value in the series of the variable. Empty if there is no last value.
- `previous`: the previous value in the series of the variable. Empty if there is no previous value.
- `next`: the next value in the series of the variable. Empty if there is no next value.
- `least`: the smallest value in the series of the variable. Empty if there is no smallest value.
- `greatest`: the largest value in the series of the variable. Empty if there is no largest value.
- `all`: all values in the series of the variable, concatenated together and separated by a comma and space. Empty if there were no values.
- `allbutlast`: all values in the series of the variable, concatenated together except for the last one, and separated by a comma and space. Empty if there were no values or only one.
- `allbutfirst`: all values in the series of the variable, concatenated together except for the first one, and separated by a comma and space. Empty if there were no values or only one.
- `unique`: all unique values in the series of the variable, concatenated together and separated by a comma and space. Empty if there were no values.
A group value is formed by the name of the group, followed by a colon in front of the variable name. Of course you can also combine group values with an alias, such as $V{least: pjt.name}.
A group value can also be used outside and after a foreach. The values of the last [<invantive:foreach>](invantive-composition-foreach-instructie) are maintained.