How can you identify a soft field on a Jepp chart?

Identifying a soft field on a Jeppesen chart is specifically marked by an "S" placed next to the runway designator. This designation alerts pilots that the runway surface is not very firm, which could affect takeoff and landing operations. Knowing that a runway has a soft surface is crucial, as it requires different handling techniques and considerations for aircraft performance, particularly concerning weight and speed management. This information helps ensure safety during operations in less-than-ideal runway conditions.

The other options, while they may seem potentially relevant, do not specifically indicate a soft field on a Jepp chart. Merely having "Soft" in notes or no specific indication wouldn't provide the necessary clarity for pilots, and highlighted runway designators may indicate other factors, such as runway type or status, rather than softness. Thus, the explicit notation of "S" next to the runway designator is the distinctive and reliable method to identify a soft field.