Documentation Typographical Conventions

Apex and Visualforce documentation uses the following typographical conventions.

Convention Description
Courier font In descriptions of syntax, monospace font indicates items that you should type as shown, except for brackets. For example:
Public class HelloWorld 
Italics In descriptions of syntax, italics represent variables. You supply the actual value. In the following example, three values need to be supplied: datatype variable_name [ = value];
If the syntax is bold and italic, the text represents a code element that needs a value supplied by you, such as a class name or variable value:
 public static class YourClassHere { ... }
Bold Courier font In code samples and syntax descriptions, bold courier font emphasizes a portion of the code or syntax.
< > In descriptions of syntax, less-than and greater-than symbols (< >) are typed exactly as shown.
<apex:pageBlockTable value="{!account.Contacts}" var="contact">
   <apex:column value="{!contact.Name}"/>
   <apex:column value="{!contact.MailingCity}"/>
   <apex:column value="{!contact.Phone}"/>
</apex:pageBlockTable>
{ } In descriptions of syntax, braces ({ }) are typed exactly as shown.
<apex:page>
    Hello {!$User.FirstName}!
</apex:page>
[ ] In descriptions of syntax, anything included in brackets is optional. In the following example, specifying value is optional:
 data_type variable_name [ = value];
| In descriptions of syntax, the pipe sign means “or”. You can do one of the following (not all). In the following example, you can create a new unpopulated set in one of two ways, or you can populate the set:
Set<data_type> set_name 
   [= new Set<data_type>();] |
   [= new Set<data_type{value [, value2. . .] };] |
   ;