The Implementation of the caption package
Axel Sommerfeldt · 2009
The caption package consists of two parts – the kernel (caption3.sty) and the main package (caption.sty). The kernel provides all the user commands and internal macros which are necessary for typesetting captions and setting parameters regarding these. While the standard LATEX document classes provide an internal command called \\@makecaption and no options to control its behavior (except the vertical skips above and below the caption itself), we provide similar commands called \\caption@make and \\caption@@make, but with a lot of options which can be selected with \\captionsetup. Loading the kernel part do not change the output of a LATEX document – it just provides functionality which can be used by LATEX 2ε packages which typesets captions, for example the caption and subfig packages. The caption package redefines the LATEX commands \\caption,