10-1
Radio code used on film sets to indicate that a crew member needs to use the bathroom, derived from police ten-code radio shorthand.
10-1
noun / exclamation | Production & On-Set
A radio code used on film and television sets to discreetly communicate that a crew member needs to use the bathroom (restroom). Derived from the ten-code system used by US law enforcement radio communications, "10-1" on a film set means a toilet break is needed. A crew member will radio the 1st AD or production assistant with "I need a 10-1" or simply say "10-1" to let the relevant person know they will be briefly off the set or away from their position. The code provides privacy for a basic human need in an environment where radio communications are heard by many people simultaneously.
Quick Reference
| Domain | Production & On-Set |
| Origin | US police/CB radio ten-code system |
| Police Meaning | "10-1" in police ten-codes means "receiving poorly" — the film set usage is a separate, informal adaptation |
| Film Set Meaning | Bathroom break needed |
| Used By | Any crew member communicating with the 1st AD or production team |
| Related Terms | Copy That, What's Your 20?, Call Sheet, Production Assistant, Wrap |
| See Also (Tools) | Shot List Generator |
| Difficulty | Foundational |
The Explanation: How & Why
Film production operates with radio communications across the entire crew — the 1st AD coordinates the set through a radio channel shared by department heads, production assistants, and key crew. When everyone is listening to the same channel, a crew member who needs to step away from their position to use the bathroom needs a way to communicate this without broadcasting personal information to the entire set.
The "10-1" code solves this problem through the shorthand of the police ten-code system, which film sets adopted informally along with other radio communication conventions. Saying "I need a 10-1" is universally understood by professional film crew and communicates the information efficiently and discreetly.
The ten-code system:
Ten-codes (also called ten signals) were developed by the Association of Public-Safety Communications Officials in 1937 to standardise radio communications for law enforcement and emergency services. The codes use "ten" plus a number to communicate common messages quickly — "10-4" means "acknowledged" or "understood"; "10-20" means "location" (as in "What's your 20?"). Film sets adopted a subset of these codes as professional vocabulary.
The note on actual ten-code meaning:
In the official police ten-code system, 10-1 means "receiving poorly" — a signal quality issue, not a bathroom break. The film industry repurposed the code informally, and its film set meaning is entirely separate from the original law enforcement meaning. Any confusion between the police meaning and the film set meaning is easily resolved by context.
Production management:
From the 1st AD's perspective, knowing that a crew member needs a 10-1 is important information for scheduling. If the camera operator needs a bathroom break, the DP needs a break, or a key department head steps away, the 1st AD must account for that absence in their timing. A 10-1 during a setup that requires that crew member's presence means the 1st AD holds the setup or adjusts the workflow until the crew member returns. Communicating the break through radio rather than simply disappearing allows the 1st AD to manage the set's timeline.
Historical Context & Origin
The adoption of ten-codes on film sets reflects the broader influence of CB radio culture and law enforcement communication practices on film production radio protocol during the 1970s and 1980s, when two-way radios became standard equipment on professional productions. The specific mapping of "10-1" to a bathroom break appears to be an informal film industry convention that emerged through usage rather than through any formal adoption of the police code. The term is standard on American film and television productions and is understood by professional crew internationally, though usage varies by country and production culture.
How It's Used in Practice
Scenario 1 -- Crew Communication (Camera Operator / 1st AD): During a lighting setup, the camera operator radios the 1st AD: "I need a 10-1 — be back in two minutes." The 1st AD acknowledges and notes the absence. The lighting setup continues; the camera operator returns before the setup is complete. No disruption to the schedule, and no awkward public announcement.
Scenario 2 -- 1st AD Scheduling (1st AD): A take has just completed. The director is conferring with the actor. The 1st AD hears three radio calls for 10-1s in quick succession — the boom operator, the best boy, and a production assistant all need breaks. The 1st AD calls a five-minute break for the set, addressing all three simultaneously and giving other crew the opportunity to step away before the next setup begins.
Scenario 3 -- New Crew Member (PA / 1st AD): A production assistant on their first day hears "10-1" over the radio and does not know what it means. They ask a more experienced PA quietly. The answer — "bathroom break" — is one of the first pieces of professional radio vocabulary they learn. By the end of the week, they are using it fluently.
Usage Examples in Sentences
"I need a 10-1. Be back in two minutes."
"Hold the setup — the focus puller called a 10-1."
"First day on set and someone asked what 10-1 meant. It is the first thing everyone learns."
"If you need a 10-1, radio the 1st AD. Do not just disappear from your position."
Common Confusions & Misuse
10-1 (film set) vs. 10-1 (police radio): In the official police ten-code system, 10-1 means "signal weak" or "receiving poorly." In film set usage, it means a bathroom break. The two meanings are entirely different; the film set adoption of the code is informal and unrelated to the original law enforcement meaning.
10-1 vs. 10-100: Some productions and individuals use "10-100" rather than "10-1" for a bathroom break — 10-100 being a code used in some radio systems specifically for that purpose. Both are understood on most professional sets; "10-1" is the more common term in American film production.
Related Terms
- Copy That -- Another radio communication term adopted from ten-code culture; means "understood" or "acknowledged"
- What's Your 20? -- A related radio code asking for a crew member's location; derived from "10-20"
- Call Sheet -- The production document that schedules the day; a 10-1 break affects the scheduling the 1st AD manages against the call sheet
- Production Assistant -- Often the crew member who relays 10-1 communications and tracks crew whereabouts for the 1st AD
- Wrap -- The end of the day when all 10-1s cease to be a scheduling consideration
See Also / Tools
The Shot List Generator relates indirectly — the 1st AD's management of 10-1 breaks is one of many real-time adjustments made to keep the shooting schedule on track, and a well-planned shot list that builds in natural transition points gives the crew opportunities for breaks without disrupting the workflow.
