In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.

Code words in text are shown as follows: "Calculations in Tcl are done by using a separate command called expr"

A block of code is set as follows:

proc createDict {} {
set value [dict create]
dict set value firstValue 1
dict set value otherValue 2
return $value
}

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

% puts [clock format [clock scan "12:45 +3 hours"]]

Tue Sep 22 15:45:00 CEST 2009

Any command-line input or output is written as follows:

set rows [mk::select myTag.people]
printRows myTag.people $rows

New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: "After a successful installation, we can go to the Administrative Tools folder and run the Services applet.".