First class mail letter 5.95 why

[myangelandmyprincess]

So I got a letter in the mail it says FCM letter the cost shows 5.95 and it has like a bar code type thing.   Any idea what kind of service this is and why it was so much for a letter rate?

[nobody*s_perfect]

It must have been one of those extra services like Certified Mail or return receipt.

https://pe.usps.com/text/dmm300/Notice123.htm#_c191

[myangelandmyprincess]

We considered certified mail but it doesn't say that anywhere on it.  We are used to those green pieces of paper for certified mail.  Not very familiar with return receipt though