This clause is informative. The following acronyms and abbreviations are used throughout this ECMA Standard. BCL -Base Class Library, which provides types to represent the built-in data types of the CLI, simple file access, custom attributes, security attributes, string manipulation, formatting, streams, and collections. CLI -Common Language Infrastructure CLS -Common Language Specification IEC -the International Electrotechnical Commission IEEE -the Institute of Electrical and Electronics Engineers ISO -the International Organization for Standardization The name C# is pronounced "C Sharp". The name C# is written as the LATIN CAPITAL LETTER C (U+0043) followed by the NUMBER SIGN # (U+000D). End of informative text.