Abstract: A highly visible pennant intended to mark a particular location is combined with a fastener permitting it to be readily attached to an existing supporting structure. The pennant may be appropriately formed of semirigid material enabling it to extend horizontally outwardly a substantial distance from the supporting structure without dropping. The fastener is positioned at one end of the pennant and the opposite, free, end is wrapped around the supporting structure, then through a receiving slot formed in the fastener, and drawn tight. The fastener, which may be integral with the pennant or of a separate construction and fixedly attached to the pennant, has a resiliently mounted clamp member with teeth positioned to permit the pennant to advance through the slot but to engage the pennant and prevent its withdrawal. A release member can be provided to enable selective removal of the pennant from the fastener.