Most faxes (and scanners, copiers, and malfunction units) require the user to put the document into the scanner either face up or face down.
There is no industry standard for the direction, and even the same manufacturer may have different systems across their product lines.
Most equipment has a logo on the document feeder similar to one of these two icons:
If it is the icon on the left, that is the symbol for fax facing up – put the document into the feeder with the blank side towards the feeder and the information side of the document facing outwards.
If it is the document on the right, that is the symbol for fax facing down – put the document into the feeder with the information side towards feeder and the blank side facing outwards.
Double sided feeders
Some equipment will be equipped with double sided feeders that can read both sides of the page.
With these it is still important to follow the instruction for which way the document should be facing, as it will make sure that your pages stay in order.