This article is from the FAQ, by with numerous contributions by others.
Neither identifiers nor keywords of the BETA language are case-sensitive.
That is, the identifier hello is the same as the identifier HELlo, and the
keyword INNER is the same as the keywork inner. However, there is one
exception from this rule. Identifiers used for declaring Externals are
case-sensitive (due to identifiers in the C programming language being
case-sensitible). Please refer to the Compiler Manual for details.