# Alone:
${SIMPLE}

# end of line
Simple value: ${SIMPLE}

# Missing curlies:
Should not be substituted: $SIMPLE

# Start of line:
${SIMPLE} and then more content.

# This is not a sub variable:
$simple

# Two values on the same line:
first: ${SUBVAL_1}, second: ${SUBVAL_2}!

# Two values on the same line, both repeated:
first: ${SUBVAL_1}, ${SUBVAL_1}, ${SUBVAL_1}, second: ${SUBVAL_2} ${SUBVAL_2}!