Region definitions are ordinary 3- or 4-field bed file format. For example:

#  comment lines can be included starting with the # symbol
chrX   151073054   151173000
chrX   151183000   151190000  optionalRegionName
chrX   151283000   151290000
chrX   151383000   151390000 

There is a limit of 1,000 defined regions. Using the upload file function will replace any existing regions. The fourth field, name, is optional and for notation purposes only; it is not used in the Table Browser. These are 0-relative coordinates, i.e. the first base on a chromosome is at position 0.

Coordinates can also be entered in the form:

chrX:151,283,001-151,290,000  optionalRegionName 
These are 1-relative coordinates, i.e. the first base on a chromosome is at position 1.