Consistent Use of Units of Measure
Organizations should strive for a "one voice" approach to developing presentations. Presentations are the organization's messages, not messages from individuals within the organization. One voice simply means consistency in the way messages are presented. In order to achieve one voice, rules of style should be established and followed by everyone in the organization. Simple style choices like a preferred method of expressing units of measure, can make a great deal of difference in how the message is perceived.
Decide which of the following you wish to use for currency: $1m, $1M, $1 million, $1,000,000, $1MM, $1mm. As you can see, there are a lot of choices, making it easy to introduce inconsistencies into your presentation.
One of the hallmarks of a professionally produced presentation is the consistent use of terms and styles.