What are those little lines at the bottom of envelopes you get in the mail?

Question

Their like these small lowercase "L's" ( llllllll ) at the bottom of envelopes. They usually come in the mail and are mostly business letters? What do they do? What are they there for?

Answer 1

It is called the POSTNET Barcode, and is used by the post office to automatically sort the mail according to the 5-digit or 9-digit ZIP code or an 11-digit Delivery Point Code (which consists of the 9-digit ZIP code plus an additional two digits), with a check digit to ensure accuracy. POSTNET stands for Postal Numeric Encoding Technique.

The POSTNET code consists of short lines and tall lines, and is basically a binary translation of the ZIP code into the POSTNET code, with tall lines representing '1' and short lines representing '0'. A single digit is represented by five vertical lines, using the following code:

0 11000
1 00011
2 00101
3 00110
4 01001
5 01010
6 01100
7 10001
8 10010
9 10100

The first and last vertical line of the entire barcode are called frames, and are not part of the actual encoding.

The very last character (just before the END frame) is the check digit, which is made by adding all of the digits in the ZIP code, and whatever number is needed to round up to the nearest tens is the check digit. Example: If the sum of ZIP code 12345 (1+2+3+4+5) is 15, adding a check digit of 5 would bring the total 20 (rounding up to the nearest tens).

Answer 2

It's like a tracking number that makes it easier for the post office to get the letter to its destination. Instead of having a real person read the zip code and decide where to put it, they just put the envelope through a machine that automatically sorts it for them. They can process more mail faster that way.

Answer 3

It is a bar code just like you might find at the supermarket. It contains various information that make sorting mail easier and faster.

Answer 4

It has to do with your address, IE...city, state, and zip code.

Answer 5

this is the us mail tracking system