Ken Thompson and Dennis Ritchie developed C language.
Well KR notation is just notations and standards used in K&R C ,ie an older version of C .
ANSI notations for C superceded the notations of KR.
There are no notations as "ANSI" alone,i think so.
Examples of notations introduced in K&R C and ANSI C are listed below :
- standard I/O library
- compound assignment operators
Ansi C :
- function prototypes
- void pointers
- support for international character sets and locales
- preprocessor enhancements
ANSI is an organisation with HeadQuarters in United States.