Conventions used

There are several text conventions used throughout this book.

Code in text: Indicates code words in the text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: “Unlike IPv4, IPv6 is a 128-bit address size of 8 hextets with 16 bits each, divided by a colon for simplicity of interpretation (for example, 2001:0DB8:85A3:0000:0000:8A2E:0370:7334).”

A block of code is set as follows:

html, body, #map {
 height: 100%; 
 margin: 0;
 padding: 0
}

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

[default]
exten => s,1,Dial(Zap/1|30)
exten => s,2,Voicemail(u100)
exten => s,102,Voicemail(b100)
exten => i,1,Voicemail(s0)

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

$ mkdir css
$ cd css

Bold: Indicates a new term, an important word, or words you see onscreen. For instance, words in menus or dialog boxes appear in bold. Here is an example: “Take the time to read the license terms. When done, select the I accept the license terms checkbox and click Next.”

Tips or important notes

Appear like this.