Shard names have the following characteristics:

• They represent a range, where the left number is included, but the right is not.
• Their notation is hexadecimal.
• They are left justified.
• A - prefix means: anything less than the RHS value.
• A - postfix means: anything greater than or equal to the LHS value.
• A plain - denotes the full keyrange.

An example of a shard name is -80 and following the rules above this means: -80 == 00-80 == 0000-8000 == 000000-800000

Similarly 80- is not the same as 80-FF because 80-FF == 8000-FF00. Therefore FFFF will be out of the 80-FF range as 80- means: ‘anything greater than or equal to 0x80

A hash vindex produces an 8-byte number. This means that all numbers less than 0x8000000000000000 will fall in shard -80. Any number with the highest bit set will be >= 0x8000000000000000, and will therefore belong to shard 80-.