Wikipedia:What MOS is NOT

There are certain things that Wikipedia's Manual of Style is not. Many people have complained that the WP:MOS documents have attempted to define too many rules for practical use, such as attempting to decide, control or ban various issues.

There are many issues to consider. Some examples:
 * In the oil and gas industry, the abbreviation/symbol "MMbbl" has been used for more than 10 years to indicate "millions of barrels" of oil. However, the WP:MOS has tried to ban use of "MM" as meaning "millions". Hence, this an area where WP:MOS should not attempt to override the standards of an entire large industry.

There are many other issues to consider, which are not yet listed here.