- Channel
- The small integer a file is opened on. The program refers to the file by that number for as long as it is open.
- Keyed file
- A data file with one or more indexes maintained inside it, so records can be fetched by key rather than searched for.
- Key segment
- A piece of a record — an offset and a length — used to build a key. Several segments concatenated make one alternate key.
- Alternate key
- An additional index on the same file, letting the application read the same records in another order. Maintained by the file system on every write.
- Template
- A string declared with named, typed, fixed-width fields, so a record read into it can be addressed by field name.
- I/O list
- A named list of variables describing a record's fields, declared once at a line number and referenced by every read and write.
- Mnemonic
- A short code in quotes inside a print statement — clear screen, reverse video, clear to end of line — translated by the runtime for the attached terminal.
- CTL
- The system variable holding a code for the key that terminated the last input. How function keys are detected.
- PRECISION
- The number of decimal places arithmetic results are carried and rounded to. Global, and consequential.
- Picture mask
- The format string in a USING clause that turns a number into aligned, punctuated output.
- Record lock
- The exclusive hold taken when a record is read for update, released when it is written back. The unit of concurrency control.
- Tokenized program
- Source stored in the runtime's internal form rather than as text. You list it to read it, and load text to change it.
- Device alias
- A configured name standing for a printer or output destination, so programs print to a name rather than to a device path.
- Spooler
- The subsystem that queues, holds and releases print output, including form control and banner handling.
- Configuration file
- The installation-wide file defining terminals, printers, aliases, path prefixes and start-up behaviour.
- Interface file
- A flat file written by one system and read by another. How most integration with the outside world is actually done.
- Nightly / month-end
- The scheduled batch routines that recalculate totals, roll periods, and produce the reports the business runs on.
- The incumbent runtime
- The commercial interpreter an installation licenses today, from whichever vendor owns the dialect it was written for.