Useful Classes
These are some classes that are important or you might find useful to add to HTML tags.
A HTML tag can have one or many classes applied to it. If more than one class is needed, they are separated by a space. Normally you can use the dialogs in the Page Editor to add or modify a tags classes, but if you need or want to know what they look like in HTML, here are a couple of examples
A Heading
img-responsive
Makes an image responsive so it will scale nicely to the container element. In other words, it will never be larger than it's container and will always appear complete on any size screen.
img-rounded
Adds rounded corners to an image (not available in IE8)
img-circle
Shapes the image to a circle (not available in IE8)
img-thumbnail
Shapes the image to a thumbnail
text-center
Center-aligns text
text-right
Right-aligns text
pull-left
Left-aligns element or contents of a container
pull-right
Right-aligns element or contents of a container
center-block
Centres any element within its container element. This includes images. The class is applied to the item to be centred the container in which it exists.