Section 8 - Definitions

8.1 Acronyms and abbreviations used in this specification

Acronyms and abbreviations used in this specification are defined as follows:

CGM	Computer Graphics Metafile
GDP	Generalized Drawing Primitive.
ISO	International Organization for Standardization.
VDC	Virtual Device Coordinates, the coordinate system of ISO/IEC 8632:1992.

8.2 Definitions

Basic values: The subset of permissible values for parameters of a CGM element that are mandatory for conformance to this specification.
Conforming PIP generator: A metafile generator that produces only conforming PIP metafiles (or can be reliably commanded to function in that mode), and additionally conforms to any additional generator requirements as explained in section 5.1.
Conforming PIP interpreter: A metafile interpreter that at least correctly interprets any conforming PIP metafile, and conforms to any additional interpreter requirements as explained in section 5.2.
Font: As defined in CGM:1992, "a collection of glyph images having the same basic design." The CGM font model is taken from ISO/IEC 9541-1:1991, the ISO font standard. Such properties as font family (e.g., Courier), font weight (e.g., bold), font posture (e.g., italic) are properties of fonts. Text display aspects such as rotation, colour, and size are text attributes, not font properties (although, ISO 9541 does define design size, minimum size, and maximum size as font properties).
Mandatory: Referring to an element or parameter value, defines an aspect which shall occur in every metafile conforming to the profile. Referring to an implementation (generator or interpreter), defines an aspect, feature, or behaviour which shall be present in every conforming implementation. Mandatory aspects and features generally include those which are essential to successful metafile interchange.
Metafile: Synonymous with CGM. A representation for the storage and transfer of graphical data and control information.
Metafile generator: The software or hardware that creates a picture or conveys information in the CGM representation.
Metafile interpreter: The software or hardware that reads a CGM and interprets the contents.
Optional: Referring to an element or parameter value, defines an aspect which may occur in metafiles conforming to the profile. Referring to an implementation (generator or interpreter), defines an aspect, feature, or behaviour which may be present in a conforming implementation.
Permissible values: The range of values for a parameter of a CGM element as specified in CGM:1992.
Profile: A specification that defines the use of a standard, and defines all possible data streams that conform to that profile. A profile insures interoperability of different/multiple implementations of a standard. In this context, it completely and unambiguously represents the information requirements for a particular application of digital graphics data. An application profile also defines requirements for implementations.
Recommended: In the context of either metafile aspects or implementation features, refers to a feature which is not mandatory but whose presence strongly improves the chances of successful metafile interchange. Conversely, absence of the aspect or feature has been observed to be a likely source of failure of successful interchange.