A substrate polishing apparatus for polishing a polishing surface of a substrate has a film thickness monitoring device for monitoring a state of a film thickness of a thin film on the polishing surface of the substrate during polishing. When a PTT conference is established, a controller determines whether an image associated with each participant invited to the PTT conference is stored in memory on the user terminal. The system further includes a tag including a processor, a radio frequency transmitter coupled to the processor, a directed light receiver coupled to the processor, and a lens having first and second major surfaces and a side surface, the tag to receive the directed light signal via the side surface and to transmit a radio frequency tag message via the radio frequency transmitter. Document specific data and text specific to individuals is provided with a document request that initiates assembly of a document.