To write source code that is useable for all source forms (free, fixed, or tab), follow these rules:
| Blanks | Treat as significant (see Section 2.3.1). |
| Statement labels | Place in column positions 1 through 5 (or before the first tab character). |
| Statements | Start in column position 7 (or after the first tab character). |
| Comment indicator | Use only !. Place anywhere except in column position 6 (or immediately after the first tab character). |
| Continuation indicator | Use only &. Place in column position 73 of the initial line and each continuation line, and in column 6 of each continuation line (no tab character can precede the ampersand in column 6). |
The following example is valid for all source forms:
Column:
12345678... 73
_________________________________________________________________________
! Define the user function MY_SIN
DOUBLE PRECISION FUNCTION MY_SIN(X)
MY_SIN = X - X**3/FACTOR(3) + X**5/FACTOR(5) &
& - X**7/FACTOR(7)
CONTAINS
INTEGER FUNCTION FACTOR(N)
FACTOR = 1
DO 10 I = N, 1, -1
10 FACTOR = FACTOR * I
END FUNCTION FACTOR
END FUNCTION MY_SIN