CSS Writing Modes is a CSS module that defines various international writing modes, such as left-to-right (e.g. used by Latin and Indic scripts), right-to-left (e.g. used by Hebrew or Arabic scripts), bidirectional (used when mixing left-to-right and right-to-left scripts) and vertical (e.g. used by some Asian scripts).
-moz-force-broken-image-icon is an extended CSS property. The value 1 forces a broken image icon even if the image has an alt attribute. When the value 0 is used the image will act as usual and only display the alt attribute.
This value for CSSbackground-image lets you use a portion of a larger image as a background. This allows you to, for example, use different parts of one larger image as backgrounds in different parts of your content.
Just like pseudo-classes, pseudo-elements are added to selectors but instead of describing a special state, they allow you to style certain parts of a document. For example, the ::first-line pseudo-element targets only the first line of an element specified by the selector.