cmBoardSwVersion is a read-only display string reporting the firmware version running on a card in major.minor.buildnumber format, for example 1.0.6. An administrator compares this across all line cards in a chassis to confirm a firmware rollout completed consistently, since a card left on an older build could behave differently under the same configuration. For example, seeing one board still at 1.0.4 while its neighbors show 1.0.6 tells the operator that card's download did not complete and needs to be repeated.