# Change in EST Usage in Notice to Airmen (NOTAM)
> **Rule** · Policy change. · Published 2015-10-05 · Effective 2015-12-15 · 80 FR 60033
## Document
- **Document number:** 2015-25192
- **Category:** other
- **Type:** Rule
- **Action:** Policy change.
- **Citation:** 80 FR 60033
- **Publication date:** 2015-10-05
- **Effective date:** 2015-12-15
## Abstract

This document provides clarity and guidance regarding the use of the contraction "EST", which stands for "Estimated", when appended to the end of validity time in a NOTAM. The FAA is taking this action to align NOTAM policy with International Civil Aviation Organization (ICAO) standards and recommended practices.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2015/10/05/2015-25192/change-in-est-usage-in-notice-to-airmen-notam)
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