MIDI is an acronym that stands for Musical Instrument Digital Interface. It is a set of standards designed in the mid 1980's to allow different musical instruments (usually keyboards) communicate with one another using digital messages.
The profit an insurance company generates after paying all claims. That is, the underwriting gain is what is left over after the premiums the company collects are added to its investment income and the amount the company pays for claims on its policies is subtracted. An underwriting gain is also called an underwriting profit.
Underwriting services are provided by some large specialist financial institutions, such as banks, insurance or investment houses, whereby they guarantee payment in case of damage or financial loss and accept the financial risk for liability arising from such guarantee.