It is not a “Regulatory” sign. Regulatory signs are black on white or white on red or a combination of those colors only. Orange and Yellow are “Warning” signs and unenforceable under the federal MUTCD.
Federal and State highways use a system which has the numbers beginning at the state line and they increase South to North and West to East. For spurs and loops it is where the highway begins. There are some state highways which do not follow this system.
Part 2 of the Federal MUTCD recommends the number tab on the sign be on the side of the sign the motorist will exit. If the tab is on the left it is a left exit, if the tab is on the right it is a right exit.
Some jurisdictions have the ramp traffic “Yield” by using a “Yield” sign at the end of the ramp. Other Jurisdictions have a law which requires the highway traffic to Yield to ramp traffic. It is all based on the jurisdictions laws.