!subsubnode Centred text
!label center environment

Lines that are part of a center environment will be displayed centred if
the destination format centred text.

You can use the center environment inside other environments. You can also
use it inside another center environment, even this may be senseless.

If you use other environments inside a center environment they will be
layouted like in all other cases. Only when the center environment is the
active one text will be printed centred.

If the following example isn't centred the current documentation format
doesn't allow it to use centred text.

!begin_quote
!begin_verbatim
!begin_center
A centred line.

A centred paragraph
with two source lines.

The Guide to (!nl)
UDO
!end_center
!end_verbatim
!end_quote

!.. will be printed in this way:

!begin_center
A centred line.

A centred paragraph
with two source lines.

The Guide to (!nl)
UDO
!end_center

You see that UDO layouts paragraphs of a center environment, too. To insert
a manual line break use the (!I)(!/nl)(!i) command.
