These Manuals aim to make it possible to give a species name in the forest to all big tree dipterocarp species. Thus, it is planned eventually to include all species that are already commercially exploited for timber, as well as the other big trees that have commercial potential. This means that the whole family is covered except for Vatica, small tree Hopea, and Cotylelobium.
The Manuals together cover all the timber-size Dipterocarpaceae that occur in the tropical rain forests of Malesia (viz. the islands of the Malay archipelago plus Peninsular Malaysia). This region has 10 genera and 386 species of Dipterocarpaceae. Forest workers, be they forester or ecologist, are often interested in a particular place where only a small fraction of this large number of species is known or can be expected to occur. Thus, to produce handy, pocket-sized books, separate Manuals are produced for different parts of the region.
The text of the Manuals includes conventional dichotomous keys based as far as possible on forest characters. It also includes full forest and botanical descriptions and notes on geographical range and ecology. Simple non-technical language is used as far as possible, consistent with precision.
In addition to the text one or more 3.5 inch diskettes are included with each Manual. These are written for use with MSDOS version 3.3 or later on IBM-PC or compatible computers with at least 256 kB RAM (but preferably 640 kB), a hard disk and a monochrome or colour screen. The diskette contains an interactive multi-access key. Dichotomous keys become difficult to use whenever more than 25-30 species are included. Multi-access keys do not suffer this problem, and when computer-based are easy to use.