Some commands will require you to provide a direction, there are quite a few ways to define directions. For simplicity purposes, all directions will be logged in either coordinate or degree form.

Cardinal Direction
You can define directions using the typical compass words: North, South, East and West, as well as Up and Down. North is -Z, East is +X, South is +Z and West is -X. If you are providing more than one direction than you should combine them. Example: northeast, southwest, upnorthwest, downsoutheast, etc. You can also shorten the directions to just their first letter, for example n would be north, sw would be southwest and une would be upnortheast.

You can also set a direction by simply defining which coordinate direction you wish to move it in. If you are defining more than one direction then they should be separated by a comma. You do not need a + for positive values. Example: x,-y,z

Some commands also use degrees to define direction, the degree variable ranges from 0-359. North is 180, East is 270, South is 0 and West is 90. Only commands which allow for high precision, such as /check dir, will use degrees.

You can also use the keywords me to use the direction you are looking in. It will be converted to one of the above formats depending on the command. You can also use me2 to ignore the y value.