Expanding Symbols

In SVG you can reuse graphics, which saves on space by avoiding duplicating content.

In our case we use this in the same way flash uses symbols, so that if a symbol is used several times (like the girls two shoes for example, which are instances of the same symbol) the symbol itself is only included once, with two reference nodes pointing to the symbol node.

'Expanding symbols' will dereference these links, replacing each reference node with a copy of the symbol node. This can increase file size but improve performance (in some settings, mobile browsers probably won't get much of a benefit, if any). That said, the reference nodes themselves are relatively big, so to try and minimise file size there is the "Expand Once Used Symbols" setting, which only expands symbols which have only one reference node, this should result in the smallest file possible.