Final answer:
The notation I:N in CVSS2 signifies that there is no integrity impact from a vulnerability exploitation, representing the least serious assessment for this metric in the Common Vulnerability Scoring System.
Step-by-step explanation:
In CVSS2#AV:N/AC:L/Au:N/C:P:/I:N/A:N, the notation I:N indicates that a successful exploitation of this vulnerability would have no integrity impact. This is the least serious value for this metric. The Common Vulnerability Scoring System (CVSS) provides an open framework for communicating the characteristics and impacts of IT vulnerabilities. The integrity impact metric assesses the potential for unauthorized modification or destruction of information. The value I:N denotes that there is no impact on integrity, whereas I:P would indicate partial impact, and I:C would indicate a complete impact.