# Industry Standard Ambiguity for Switches Explained

**URL:** <https://forum.digikey.com/t/industry-standard-ambiguity-for-switches-explained/56274>\
**Category:** Switches\
**Tags:** faqs, tech-tips\
**Created:** [June 11, 2025, 8:51pm UTC](https://forum.digikey.com/t/industry-standard-ambiguity-for-switches-explained/56274 "2025-06-11T20:51:41Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Kaleb\_Kohlhase](https://sea2.discourse-cdn.com/digikey/user_avatar/forum.digikey.com/kaleb_kohlhase/32/59963_2.png) [@Kaleb\_Kohlhase](https://forum.digikey.com/u/Kaleb_Kohlhase)\
**Post date:** [June 11, 2025, 8:51pm UTC](https://forum.digikey.com/t/industry-standard-ambiguity-for-switches-explained/56274/1 "2025-06-11T20:51:41Z")

</div>

Sometimes manufacturers refer to **industry standards** in their datasheets or drawings without explaining them, which can be confusing for those new to switches.

One such standard involves the use of **parentheses around switch actions.** For example, the manufacturer part number PA412C1100 (DigiKey part number [EG4688-ND](https://www.digikey.com/en/products/detail/e-switch/PA412C1100/2116167?s=N4IgTCBcDaIAoEEAsBGMBhFKAM2QF0BfIA)) includes a part builder in its datasheet that breaks down the part number:

- **PA4** is the series
- **1** indicates 4.8mm tabs
- **2** means it’s a 2-pole switch with an Off-On function

Now, if you were to replace the “2” with an “ **E** ”, the datasheet shows **Off-(On)** – but doesn’t explain what that means.

Here’s the key: **When a switch action is shown in parentheses, it indicates a momentary function.**

So **Off-(On)** means the switch returns to Off when released – a momentary On. In contrast, **Off-On** means the switch toggles and stays in the On position until pressed again. This means that **PA412C1100** is a **non-momentary toggle switch**. Understanding this notation will help comparing or selecting other variants.