Each type of component has a two-dimensional symbol which is used to represent it on the isometric drawings. Each symbol is referred to by a text attribute, known as the symbol key (SKEY) attribute, of a DTEXT element.

The chapter Symbol Keys of the ISODRAFT Reference Manual contains a complete list of the standard symbols and their associated symbol keys, grouped together by generic type (ELBO, FLAN, PCOM, VALV, etc.).

The user can usually select any symbol listed under the relevant generic type. For example, the following symbol keys are valid for a CAP, refer to CAP Symbol Keys of the ISODRAFT Reference Manual:

where symbolkeytext is the symbol key attribute code enclosed between closing quotes. For example:

The default SKEY symbols should be suitable for most applications. For specialised needs it is possible to redefine existing symbols, or to create new symbols, for some types of component. This is described in the chapter Symbol Keys.