Many of the examples in this book are based on the development of the "Wineco protocol." This is a fictitious protocol, used simply to illustrate various parts of ASN.1. The first parts of it appear in Figure 2.1, and a full copy of the final protocol is given in Appendix 2.

Wineco is a company that sells wine from a variety of outlets and owns two ware-houses, one northern and one southern. Initially all outlets were in the UK only (where the name of an outlet could be supported by the ASCII character set), but later Wineco extended to overseas territories, where a larger character set was needed.

In Figure 2.1 we see one of the messages we use in the protocol, "Order-for-stock" to request a number of cases of particular types of wine with a specified urgency. We also see the form of a "Branch-identification" type.

In Chapter 3 we add the necessary module headers, and some extensibility markers with an insertion point not at the end. Later we turn it into a multimodule specification with "common types" in one module, the top-level type in another, and the ordering protocol message "Order-for-stock" in a third. We also introduced a second top-level message in Figure 3.8,...