A method for delivering person to person services to a telephone subscriber. Narrowbroad band filters produced with vacuum deposited multilayered thin films are designed to selectively reflecttransmit light at specific wavelengths. This invention accomplishes the described objectives in file system security by creating an external database containing auxiliary attributes for objects in the file system. The concentration of nitrogen in the region is inferred and used to trigger an \u201cexplosive found\u201d or a \u201cno explosive found\u201d signal. Pairs of opposed gaps of the cap and the hub are aligned with lines of weakness or seams of the sheath tube and the weak bond of the valve, facilitating splitting of the assembly when desired by the practitioner to peel it away from the inserted catheter.