MCForms format and operating notes.

Basic payload format

A raw MCForms payload begins with the form ID, followed by encoded responses, optional prompt fields, optional comment text, and optional datecode.

F!101 232335222 Bad Propagation #FJDE

Optional station or group addressing belongs outside the raw payload.

@ARCWC F!101 232335222 Bad Propagation #FJDE

Cross-mode declaration

When sending outside JS8Spotter/JS8Call, add a short declaration so the recipient knows the text is an MCForms payload.

MCFORMS F!101 232335222 Bad Propagation #FJDE
MCF F!101 232335222 Bad Propagation #FJDE

MCFORMS is clearer. MCF is shorter for tighter paths.

Prompt fields

Prompt fields use two-character IDs such as [ST], [GR], [CT], and [ET]. Keep them short.

Recommended location use: state, tactical area, or Maidenhead grid. Put town, address, landmark, or detail in the comment only when needed.

Form ID numbering convention

Use these ranges when creating or publishing additional forms so operators avoid collisions. Same Form ID should mean the same form definition. If you change the questions, answers, prompt fields, or meaning of a form, use a different unused Form ID.

• 000-099: preliminary or proposed forms
• 100-199: informational, informal, non-emergency
• 200-299: reserved for future allocation
• 300-399: emergency, exercise, and situation reports
• 400-499: reserved for future allocation
• 500-599: surveys of general conditions
• 600-699: reserved for future allocation
• 700-799: group and net forms
• 800-899: reserved for future allocation
• 900-999: miscellaneous, overflow, local, or experimental use

Optional authentication code

Some operators may append a three-character authentication code after the datecode.

F!101 232335222 Bad Propagation #FJDE 20S

MCForms.org carries and labels this code but does not generate or validate it. Validation requires the outside authentication method and shared key agreed to by the operators.

Datecode

The datecode begins with # and uses four compact characters for month, day, hour, and two-minute-resolution minute.

#FJDE

MCForms.org generates datecodes using UTC. The datecode does not include a year.

Typical character targets

• APRS message: about 67 characters
• SMS GSM: 160 characters
• SMS Unicode: 70 characters
• Meshtastic conservative target: about 200 characters
• General low-bandwidth target: about 240 characters

Treat these as practical planning targets, not universal guarantees.

Original implementation reference

One of the earliest and most widely used implementations of MCForms was developed for the JS8Spotter ecosystem by Joe Lyman, KF7MIX.

The primary JS8Spotter MCForms repository is maintained by SITREPNET.