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COBOL Data Names

Data names are identifiers used to name data items, variables, and data structures in COBOL programs. Learn naming conventions, rules, and best practices for creating meaningful and maintainable data names.

Data Name Rules and Syntax

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       WORKING-STORAGE SECTION.
       01 VALID-DATA-NAMES.
           05 CUSTOMER-ID PIC 9(6).              *> Valid: starts with letter
           05 CUSTOMER-NAME PIC X(30).            *> Valid: contains hyphen
           05 ACCOUNT-BALANCE PIC 9(9)V99.       *> Valid: descriptive name
           05 TRANSACTION-COUNT PIC 9(4).        *> Valid: meaningful name
           05 DATE-OF-BIRTH PIC 9(8).            *> Valid: clear purpose
       
       *> Invalid data names (commented out):
       *> 05 123-INVALID PIC 9(6).               *> Invalid: starts with digit
       *> 05 CUSTOMER-NAME- PIC X(30).           *> Invalid: ends with hyphen
       *> 05 -INVALID-NAME PIC X(20).            *> Invalid: starts with hyphen
       *> 05 PERFORM PIC X(10).                  *> Invalid: reserved word

Follow COBOL data name rules: start with a letter, use only letters/digits/hyphens, 1-30 characters, no reserved words, and don't start/end with hyphens. Use descriptive names that clearly indicate purpose.

Naming Conventions

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       WORKING-STORAGE SECTION.
       01 NAMING-CONVENTIONS.
           05 INPUT-DATA.
               10 INPUT-CUSTOMER-ID PIC 9(6).
               10 INPUT-CUSTOMER-NAME PIC X(30).
               10 INPUT-TRANSACTION-AMOUNT PIC 9(9)V99.
           05 OUTPUT-DATA.
               10 OUTPUT-CUSTOMER-ID PIC 9(6).
               10 OUTPUT-CUSTOMER-NAME PIC X(30).
               10 OUTPUT-TOTAL-BALANCE PIC 9(9)V99.
           05 WORK-VARIABLES.
               10 WS-COUNTER PIC 9(4).
               10 WS-TEMP-AMOUNT PIC 9(9)V99.
               10 WS-FLAG PIC X.
           05 CONSTANTS.
               10 C-MAX-RECORDS PIC 9(4) VALUE 1000.
               10 C-COMPANY-NAME PIC X(20) VALUE 'ACME CORP'.
               10 C-DEFAULT-STATUS PIC X VALUE 'A'.

Use consistent naming conventions with prefixes: INPUT- for input data, OUTPUT- for output data, WS- for work variables, C- for constants. This improves code readability and maintainability.

Descriptive Data Names

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       WORKING-STORAGE SECTION.
       01 DESCRIPTIVE-NAMES.
           05 CUSTOMER-MASTER-RECORD.
               10 CUSTOMER-UNIQUE-IDENTIFIER PIC 9(6).
               10 CUSTOMER-FULL-NAME PIC X(50).
               10 CUSTOMER-ACCOUNT-BALANCE PIC 9(9)V99.
               10 CUSTOMER-ACCOUNT-STATUS PIC X.
                   88 CUSTOMER-ACCOUNT-ACTIVE VALUE 'A'.
                   88 CUSTOMER-ACCOUNT-INACTIVE VALUE 'I'.
               10 CUSTOMER-LAST-TRANSACTION-DATE PIC 9(8).
               10 CUSTOMER-CREDIT-LIMIT PIC 9(9)V99.
       
       PROCEDURE DIVISION.
       DISPLAY 'Customer ID: ' CUSTOMER-UNIQUE-IDENTIFIER
       DISPLAY 'Customer Name: ' CUSTOMER-FULL-NAME
       DISPLAY 'Account Balance: ' CUSTOMER-ACCOUNT-BALANCE
       
       IF CUSTOMER-ACCOUNT-ACTIVE
           DISPLAY 'Account is active'
       END-IF.

Use descriptive data names that clearly indicate the data's purpose and context. Include relevant qualifiers like CUSTOMER-, ACCOUNT-, TRANSACTION- to make names self-documenting and meaningful.

Group and Elementary Item Names

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       WORKING-STORAGE SECTION.
       01 GROUP-AND-ELEMENTARY-NAMES.
           05 EMPLOYEE-INFORMATION.              *> Group item name
               10 EMPLOYEE-ID PIC 9(6).          *> Elementary item name
               10 EMPLOYEE-PERSONAL-DATA.        *> Sub-group name
                   15 EMPLOYEE-FIRST-NAME PIC X(15).
                   15 EMPLOYEE-LAST-NAME PIC X(20).
                   15 EMPLOYEE-MIDDLE-INITIAL PIC X.
               10 EMPLOYEE-WORK-DATA.            *> Sub-group name
                   15 EMPLOYEE-DEPARTMENT PIC X(10).
                   15 EMPLOYEE-POSITION PIC X(20).
                   15 EMPLOYEE-SALARY PIC 9(7)V99.
               10 EMPLOYEE-ADDRESS-DATA.         *> Sub-group name
                   15 EMPLOYEE-STREET-ADDRESS PIC X(30).
                   15 EMPLOYEE-CITY PIC X(20).
                   15 EMPLOYEE-STATE PIC X(2).
                   15 EMPLOYEE-ZIP-CODE PIC X(10).
       
       PROCEDURE DIVISION.
       *> Access group items
       DISPLAY 'Employee: ' EMPLOYEE-PERSONAL-DATA
       DISPLAY 'Work Info: ' EMPLOYEE-WORK-DATA
       
       *> Access elementary items
       DISPLAY 'ID: ' EMPLOYEE-ID
       DISPLAY 'Name: ' EMPLOYEE-FIRST-NAME ' ' EMPLOYEE-LAST-NAME.

Name group items to represent logical data groupings and elementary items to represent individual data fields. Use hierarchical naming to show relationships between data items.

File and Record Names

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       FILE SECTION.
       FD CUSTOMER-MASTER-FILE                   *> File name
           LABEL RECORDS ARE STANDARD
           RECORDING MODE IS F.
       01 CUSTOMER-MASTER-RECORD.                *> Record name
           05 CUSTOMER-RECORD-HEADER.
               10 CUSTOMER-RECORD-TYPE PIC X VALUE 'C'.
               10 CUSTOMER-RECORD-SIZE PIC 9(4).
           05 CUSTOMER-RECORD-DATA.
               10 CUSTOMER-RECORD-ID PIC 9(6).
               10 CUSTOMER-RECORD-NAME PIC X(30).
               10 CUSTOMER-RECORD-BALANCE PIC 9(9)V99.
       
       FD TRANSACTION-DETAIL-FILE                *> File name
           LABEL RECORDS ARE STANDARD
           RECORDING MODE IS F.
       01 TRANSACTION-DETAIL-RECORD.             *> Record name
           05 TRANSACTION-RECORD-ID PIC 9(8).
           05 TRANSACTION-RECORD-DATE PIC 9(8).
           05 TRANSACTION-RECORD-AMOUNT PIC 9(9)V99.
           05 TRANSACTION-RECORD-DESCRIPTION PIC X(50).

Use descriptive names for files and records that indicate their purpose and content. Include file type indicators like MASTER, DETAIL, SUMMARY, and record type indicators like HEADER, DATA, TRAILER.

Condition Names (88-levels)

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       WORKING-STORAGE SECTION.
       01 CONDITION-NAMES.
           05 ACCOUNT-STATUS PIC X.
               88 ACCOUNT-STATUS-ACTIVE VALUE 'A'.
               88 ACCOUNT-STATUS-INACTIVE VALUE 'I'.
               88 ACCOUNT-STATUS-SUSPENDED VALUE 'S'.
               88 ACCOUNT-STATUS-CLOSED VALUE 'C'.
           05 TRANSACTION-TYPE PIC X.
               88 TRANSACTION-TYPE-DEPOSIT VALUE 'D'.
               88 TRANSACTION-TYPE-WITHDRAWAL VALUE 'W'.
               88 TRANSACTION-TYPE-TRANSFER VALUE 'T'.
               88 TRANSACTION-TYPE-FEE VALUE 'F'.
           05 CUSTOMER-GRADE PIC 9.
               88 CUSTOMER-GRADE-PREMIUM VALUE 9 8.
               88 CUSTOMER-GRADE-STANDARD VALUE 7 6 5.
               88 CUSTOMER-GRADE-BASIC VALUE 4 3 2 1.
       
       PROCEDURE DIVISION.
       IF ACCOUNT-STATUS-ACTIVE
           DISPLAY 'Account is active'
       END-IF
       
       IF TRANSACTION-TYPE-DEPOSIT
           DISPLAY 'Processing deposit'
       END-IF
       
       IF CUSTOMER-GRADE-PREMIUM
           DISPLAY 'Premium customer'
       END-IF.

Use meaningful condition names (88-levels) that clearly describe the condition being tested. Include the data item name as a prefix and use descriptive suffixes for different values.

Array and Table Names

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       WORKING-STORAGE SECTION.
       01 ARRAY-AND-TABLE-NAMES.
           05 CUSTOMER-TABLE OCCURS 100 TIMES.
               10 CUSTOMER-TABLE-ID PIC 9(6).
               10 CUSTOMER-TABLE-NAME PIC X(30).
               10 CUSTOMER-TABLE-BALANCE PIC 9(9)V99.
           05 MONTHLY-SALES-ARRAY OCCURS 12 TIMES.
               10 MONTHLY-SALES-AMOUNT PIC 9(9)V99.
               10 MONTHLY-SALES-COUNT PIC 9(6).
           05 STATE-TAX-RATE-TABLE OCCURS 50 TIMES.
               10 STATE-TAX-RATE-CODE PIC X(2).
               10 STATE-TAX-RATE-PERCENTAGE PIC 9(3)V99.
       
       PROCEDURE DIVISION.
       *> Access array elements
       MOVE 1000.50 TO MONTHLY-SALES-AMOUNT(1)
       MOVE 1500.75 TO MONTHLY-SALES-AMOUNT(2)
       
       DISPLAY 'January sales: ' MONTHLY-SALES-AMOUNT(1)
       DISPLAY 'February sales: ' MONTHLY-SALES-AMOUNT(2).

Use descriptive names for arrays and tables that indicate their purpose and content. Include TABLE or ARRAY in the name and use meaningful suffixes for array elements.

Parameter and Linkage Names

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       LINKAGE SECTION.
       01 PARAMETER-AND-LINKAGE-NAMES.
           05 INPUT-PARAMETER-AREA.
               10 INPUT-PARAMETER-LENGTH PIC S9(4) COMP.
               10 INPUT-PARAMETER-DATA PIC X(100).
           05 OUTPUT-PARAMETER-AREA.
               10 OUTPUT-PARAMETER-RETURN-CODE PIC 9(4).
               10 OUTPUT-PARAMETER-MESSAGE PIC X(50).
           05 SHARED-DATA-AREA.
               10 SHARED-DATA-CUSTOMER-ID PIC 9(6).
               10 SHARED-DATA-CUSTOMER-NAME PIC X(30).
               10 SHARED-DATA-CUSTOMER-BALANCE PIC 9(9)V99.
       
       PROCEDURE DIVISION USING INPUT-PARAMETER-AREA
                                OUTPUT-PARAMETER-AREA
                                SHARED-DATA-AREA.
       DISPLAY 'Input parameter length: ' INPUT-PARAMETER-LENGTH
       DISPLAY 'Shared customer ID: ' SHARED-DATA-CUSTOMER-ID.

Use clear names for parameters and linkage data that indicate their purpose and direction. Include INPUT-, OUTPUT-, SHARED- prefixes to clarify data flow and usage.

Data Name Best Practices

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       WORKING-STORAGE SECTION.
       01 DATA-NAME-BEST-PRACTICES.
           05 PROGRAM-CONSTANTS.
               10 C-MAXIMUM-RECORD-COUNT PIC 9(4) VALUE 1000.
               10 C-MINIMUM-BALANCE-THRESHOLD PIC 9(9)V99 VALUE 100.00.
               10 C-DEFAULT-INTEREST-RATE PIC 9(3)V99 VALUE 5.25.
           05 PROGRAM-VARIABLES.
               10 WS-RECORD-COUNTER PIC 9(6) VALUE 0.
               10 WS-TOTAL-AMOUNT PIC 9(9)V99 VALUE 0.
               10 WS-PROCESSING-FLAG PIC X VALUE 'N'.
                   88 WS-PROCESSING-COMPLETE VALUE 'Y'.
           05 BUSINESS-DATA.
               10 CUSTOMER-ACCOUNT-NUMBER PIC 9(8).
               10 CUSTOMER-ACCOUNT-BALANCE PIC 9(9)V99.
               10 CUSTOMER-ACCOUNT-INTEREST-RATE PIC 9(3)V99.
       
       PROCEDURE DIVISION.
       *> Use meaningful names that describe business purpose
       MOVE C-MINIMUM-BALANCE-THRESHOLD TO WS-TOTAL-AMOUNT
       
       IF CUSTOMER-ACCOUNT-BALANCE > C-MINIMUM-BALANCE-THRESHOLD
           DISPLAY 'Account meets minimum balance requirement'
       END-IF.

Follow best practices: use meaningful names that describe business purpose, maintain consistent naming conventions, avoid abbreviations that reduce clarity, and group related data with common prefixes.

Common Naming Patterns

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       WORKING-STORAGE SECTION.
       01 COMMON-NAMING-PATTERNS.
           05 FILE-NAMES.
               10 CUSTOMER-MASTER-FILE PIC X(20).
               10 TRANSACTION-DETAIL-FILE PIC X(20).
               10 REPORT-OUTPUT-FILE PIC X(20).
           05 RECORD-NAMES.
               10 CUSTOMER-MASTER-RECORD PIC X(20).
               10 TRANSACTION-DETAIL-RECORD PIC X(20).
               10 REPORT-HEADER-RECORD PIC X(20).
           05 FIELD-NAMES.
               10 CUSTOMER-ID-FIELD PIC X(20).
               10 TRANSACTION-AMOUNT-FIELD PIC X(20).
               10 REPORT-DATE-FIELD PIC X(20).
           05 WORK-VARIABLES.
               10 WS-FILE-STATUS PIC X(20).
               10 WS-RECORD-COUNT PIC X(20).
               10 WS-TOTAL-AMOUNT PIC X(20).
           05 CONSTANTS.
               10 C-MAX-RECORDS PIC X(20).
               10 C-DEFAULT-VALUE PIC X(20).
               10 C-ERROR-MESSAGE PIC X(20).

Use common naming patterns: FILE- for file names, RECORD- for record names, FIELD- for field names, WS- for work variables, C- for constants. This creates consistent and predictable naming throughout programs.

Data Movement

Data transfer and migration

Data Definition

Declaring variables and data structures