Check the wiki following the UM instruction (e.g. the user instead of they)

check to include a typical scenario for each use case, expressed in natural language in one of several possible formats
- the format of Lihua Ou's WD-Pic User's Manual,
- multicolumn format as in the Scenarios and Use Cases slides,
- single column, multicolor format, with the steps of each actor or process being in a different color,
- the format of Adobe Acrobat's online help pages,
check to include all needed exceptional scenarios for each use case, especially to deal with assumptions that do not hold,
check to include all needed alternative scenarios for each use case, and
check to include a user-interface description that is associated with these scenarios. If applicable.

Edited Jul 06, 2020 by shibohan