The RFIND function searches a string for a sub-string of characters beginning with the right-most character in a string and based on the function’s context, returns the sub-string when found, the position of the first character of the sub-string within the source string, or an indictor of whether the sub-string was found. This search can optionally be case-insensitive and may begin at the right-most character of the source string, or somewhere within the source string by specifying the first position, counting from the left, to begin searching.
When RFIND is called in a string context, the function will search a source string for a sub-string, returning that sub-string when found, or an empty string if not found.
When RFIND is called in an integral number context, the function will search a source string for a sub-string, returning the position of the first character of the sub-string within the source string when found, or -1 if not found. The left-most character of the source string is at position 0.
When RFIND is called in a Boolean context, the function will search a source string for a sub-string, returning true when found, or false if not found.