Editing IBM RPG II (section)

==  Indicators ==
Indicators are either 'set' or not, they are [[Flag (computing)|"flags"]] or [[boolean data type]]s.
* Generic, usually manually set, for custom usage within ''I'', ''C'' and ''O'' specs of a program:
:: &nbsp;&nbsp;&nbsp;&nbsp; 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19
:: 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39
:: 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59
:: 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79
:: 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99
* Halt Indicators, manually set within the calculation ''C''-specs, to terminate a program with a return code:
:: H1 H2 H3 H4 H5 H6 H7 H8 H9
* Matching Indicators, assigned to input ''I''-spec fields, automatically set when reading records from a file, to coordinate the hierarchy of and signal which fields (variables) within records from two or more files are synchronized, assuming a sorted order of the records within each file, the records being processed sequentially:
:: M1 M2 M3 M4 M5 M6 M7 M8 M9, and {{code|MR}} which reflects that matching has occurred
* Control-Level Indicators, assigned to input ''I''-spec fields, to coordinate the hierarchy of and signal which fields within a record from a file are grouped, assuming a sorted order of the records within a file, the records being processed sequentially:
:: L0 L1 L2 L3 L4 L5 L6 L7 L8 L9
* Command Key Indicators, to signal to the program processing input from a workstation keyboard, equivalent to the function keys ({{code|F1-F12}}, and {{code|shift-F1-F12}}) on a PC keyboard, used instead of the {{code|Enter}} key:
:: KA KB KC KD KE KF KG KH KI KJ KK KL KM KN KP KQ KR KS KT KU KV KW KX KY
:: These indicators refer to command keys 1 to 24, in that order.  Note that there is no {{code|KO}} indicator.
* First Cycle Indicator, set automatically upon output of the first page, mainly used for printer files, used similarly to an overflow indicator for controlling output like page breaks and headings:
:: 1P
* Overflow Indicators, tripped automatically processing the pagination limits of a printer output file, per each file's ''L''-spec line counter, and may be set manually, too. Usually establishing page breaks and printing of headings. One indicator each, for up to 8 output files:
:: OA OB OC OD OE OF OG OV
* Last Record Indicator, not to be confused with Control-Level indicators, terminates a program, to return control to the batch processing jobstream (script), set automatically when end-of-file is reached on a sequentially processed file, manually set to terminate a program that has no sequential process source (file):
:: LR
* External Indicators, generic for custom usage, passed to the program from the jobstream control (script) batch file:
:: U1 U2 U3 U4 U5 U6 U7 U8

Foldable sheets, templates, plastic coated against wear and staining, were available, summarizing the different specifications. Used for the visual inspection and verification of the fixed-format source code text when held against its printed output. They matched and aligned with the then standard spacing of the text, as drawn from the original usage of [[punched card]]s:
{| class="wikitable" border="1" width="25%"
|+ System/36 SEU templates
|-  
| 3
| H || header
|-  
| 5
| F || files
|-  
| 6
| F || extensions
|-  
| 7
| E || extensions
|-  
| 8
| L || line counters
|-  
| 10
| I || file
|-  
| 11
| I || fields
|-  
| 12
| C || calculation
|-  
| 13
| O || file
|-  
| 14
| O || fields
|}