Hypertext links connect two or more pieces of text, which may or may not be part of the same "book". The presence of these links is usually indicated by a "hot word" - a word coloured differently to the rest of the text, often in blue, or other symbol. Virtual Worlds of Girls uses symbols such as to denote the presence of links, in order to delineate between types of links.

Alternatively, the presence of a link may only be indicated when the reader passes over it, for example by a word changing colour at that point.

Bob Cotton and Richard Oliver explain that:

[Ted] Nelson's concept of "chunk" hypertext (such as the extra notes, marginalia or references linked to the main text via "asterisk" buttons and only visible if required) and "collateral" hypertext (where two related passages of text are linked together with perhaps some mediating explanation of the link) are the two main ways in which most hypermedia programmes use hypertext. The central idea is to provide the reader with a variety of different perspectives on to a body of information that can be stored interactively.

(Understanding Hypermedia, Phaidon Press Ltd, London, 1993, p53)

Dr Ju Gosling aka ju90's ABNORMAL: How Britain became body dysphoric and the key to a cure is available now for just £3.09 for the Kindle or in a limited-edition hardback with full-colour art plates for £20 inc UK postage and packing.