Most Digital Cinema Packages are now being distributed in the SMPTE-DCP format. Prior packages adhered to the Interop-DCP format. The design of these Interop packages adheres to a de facto standard that was common practice. The industry has moved to the formal SMPTE (Society of Motion Picture and Television Engineers) standards. This mainly impacts servers, not projectors; however, rendering of subtitles in the projectors may be affected. In order to identify the construction of the package, the standard is explicitly denoted IOP for an Interop-DCP package and SMPTE for a SMPTE-DCP package. Additionally, if the package is a 3D package the extension of -3D is added to the field. This is done so that a quick check of the end of the file name indicates the standard and whether or not the package is in 3D.