Where are the Replacement Vars from vB2? 
If you have upgraded to vBulletin 3 from a previous installation of vBulletin 2, you will probably know that in vBulletin 2, replacement variables were used extensively in the default vBulletin style to control various facets of the style, such as colors and fonts. In vBulletin 3 however, there are no replacement variables used in the default style.

Where did they all go?

The answer is that all of the replacement variables from vBulletin 2 have been translated into CSS classes, or have been migrated to the new StyleVars system.

The new systems are less processor-intensive (easier on your server's resources) than using replacement variables, and offer a lot more flexibility in the way that they can be used.

The following table lists all the default vBulletin 2 replacement variables, and shows how they have been translated for use in vBulletin 3.
Item NameReplacement TextvBulletin 3 EquivalentDescription
HTML Doctype{htmldoctype}StyleVar:
HTML Doctype
The HTML Doctype replacement variable has been migrated directly to the HTML Doctype StyleVar.
Body Tag<body>CSS:
Body class
All attributes controlled by the <body> tag replacement variable in vBulletin 2 are now managed by the Body CSS class.
Main Table Width{tablewidth}StyleVar:
Main Table Width
The width of vBulletin tables; controlled by the {tablewidth} replacement variable in vBulletin 2, is now controlled by the Main Table Width StyleVar.
Content Table Width{contenttablewidth}StyleVar:
Spacer Size
The width of tables inside the main page body; previously controlled by the {contenttablewidth} replacement variable, is now handled in a different way by the Spacer Size StyleVar.
Outer Borders Width{tableouterborderwidth}CSS:
Table Border class
The width of the border around tables in vBulletin is now controlled via CSS as part of the Table Border class.
Inner Borders Width{tableinnerborderwidth}StyleVar:
Inner Border Width
Control of the amount of spacing between table cells has been transferred to the Inner Border Width StyleVar.
'Extra' Table Attributes{tableouterextra}
n/aIn vBulletin 2 these replacement variables were used to allow arbitrary code to be inserted into <table> tags. This functionality is no longer necessary, as any code that might have been inserted here can now be emulated using CSS.
Page Background / Text Colors{pagebgcolor}
Page Background class
The background color and text color of the main page body is now controlled by the Page Background CSS class.
Table Border Color{tablebordercolor}CSS:
Table Border class
The {tablebordercolor} replacement variable was used to set the color of all borders around and inside <table> tags in vBulletin 2. This functionality is now managed by CSS in the Table Border class.
Category Strip Background / Text Colors{categorybackcolor}
Category Strips class
The background and text colors used in category strips and main table title bars is now controlled by the Category Strips CSS class.
Table Heading Background / Text Colors{tableheadbgcolor}
Table Header class
Previously controlled by the {tableheadbgcolor} and {tableheadtextcolor} replacement variables, the style of column headings is now a part of the Table Header CSS class.
First Alternating Table Background Color{firstaltcolor}CSS:
First Alternating Color class
In vBulletin 2, only the background color of elements using the First Alternating Color could be specified. In vBulletin 3 the First Alternating Color CSS class allows significantly more control.
Second Alternating Table Background Color{secondaltcolor}CSS:
Second Alternating Color class
Partnering the First Alternating Color CSS class, the Second Alternating Color CSS class defines the style of elements previously colored with the {secondaltcolor} replacement variable.
Hyperlink Normal / Hover Colors{linkcolor}
Body and Page Background classes
vBulletin 2 allowed administrators to control the color of standard hyperlinks, and to also specify a color for those links when a mouse pointer is hovered over them. In vBulletin 3, almost every individual CSS class can define its own settings for hyperlink styling, although it is often the case that only the Body CSS class will have link styles defined, in which case this class will control all hyperlinks.
Time Color{timecolor}CSS:
Time Color class
In order to control the color of times shown on vBulletin pages, it is now necessary to look at the Time Color class, which allows not only the color but a variety of other attributes to be controlled for the styling of time displays.
Calendar Colors{calbgcolor}
n/aThe various colors defined by the calendar color replacement variables in vBulletin 2 have become redundant with the new calendar system in vBulletin 3.
Image Folder Path{imagesfolder}StyleVar:
Image Directory Paths
While vBulletin 2 defined a single images directory with the {imagesfolder} replacement variable, vBulletin 3 defines a variety of folders to serve different purposes. These are controlled by the Image Directory Paths StyleVars.
Title Image Path{titleimage}StyleVar:
Title Image
The path controlled by the Title Image Path replacement variable is now controlled by the Title Image StyleVar in vBulletin 3.
New Thread / Reply / Closed Image Paths{newthreadimage}
n/aWhile vBulletin 2 specified replacement variables for three button images relating to posting new threads and replying to posts, all of these images are now found in the $stylevar[imgdir_button] StyleVar, one of the Image Directory Path StyleVars.
Main Font<normalfont>CSS:
Body and <td>, <th>, <p>, <li> classes
In vBulletin 2 it was necessary to surround all text with <normalfont> tags in order to have it use the fonts and sizes specified. In vBulletin 3 this is no longer the case, and text display is controlled by the Body and <td>, <th>, <p>, <li> CSS classes.
Small Font<smallfont>CSS:
Small Font class
When a smaller-than-normal font size is required in vBulletin 3, it is a simple matter of applying the Small Font CSS class to an HTML tag surrounding the text to be made small.
Large Font<largefont>n/aThe <largefont> replacement variable was used so infrequently in vBulletin 2 that it was decided not to waste resources on replicating it in vBulletin 3, so it is no longer available.
Highlighted Font<highlight>CSS:
Highlighted Font class
In vBulletin 2 the color of highlighted text was controlled by the <highlight> replacement variable, but much more control is afforded by the vBulletin 3 Highlighted Font CSS class that replaces it.
Textarea Column Settings{textareacols_IE}
n/aIn the bad old days before CSS was widely supported by browsers it was necessary to rely on the cols="x" attribute of <textarea> tags to specify the width of a <textarea>. Different browsers interpreted this value with a different resultant width, resulting in the need for a set of replacement variables in order to achieve roughly the same width for <textarea> tags in all browsers. With CSS the 'width' style attribute can be used to control the width more precisely, rendering these three replacement variables obsolete.
With the information in this table, your transtion from the vBulletin 2 styles system to the vBulletin 3 system should be as painless as possible.
User Contributed Notes: Where are the Replacement Vars from vB2?