# Official Sources
This page lists authoritative sources for XPT format and regulatory requirements.
## SAS Documentation
### TS-140: XPT V5 Specification
**The authoritative specification for XPT V5 format.**
- **Title**: Record Layout of a SAS Version 5 or 6 Data Set in SAS Transport (XPORT) Format
- **Publisher**: SAS Institute Inc.
- **Link**: [TS-140 PDF](https://support.sas.com/content/dam/SAS/support/en/technical-papers/record-layout-of-a-sas-version-5-or-6-data-set-in-sas-transport-xport-format.pdf)
Key contents:
- File structure (headers, NAMESTR, observations)
- 140-byte NAMESTR record layout
- IBM floating-point encoding
- Character encoding rules
## FDA Documentation
### Study Data Technical Conformance Guide
**Requirements for electronic study data submissions.**
- **Publisher**: U.S. Food and Drug Administration
- **Link**: [TCG PDF](https://www.fda.gov/media/153632/download)
Key contents:
- Required file formats (XPT V5)
- File size limits (5GB)
- Character encoding (ASCII)
- eCTD placement
### FDA Data Standards Catalog
**Supported CDISC standards and versions.**
- **Link**: [Data Standards Resources](https://www.fda.gov/industry/fda-data-standards-advisory-board/study-data-standards-resources)
## CDISC Standards
### SDTM Implementation Guide
**Standard for tabulation data structure.**
- **Publisher**: CDISC
- **Link**: [SDTM-IG](https://www.cdisc.org/standards/foundational/sdtmig)
Key contents:
- Domain structures (DM, AE, LB, etc.)
- Variable naming conventions
- Controlled terminology requirements
- Metadata requirements
### ADaM Implementation Guide
**Standard for analysis datasets.**
- **Publisher**: CDISC
- **Link**: [ADaM-IG](https://www.cdisc.org/standards/foundational/adam)
Key contents:
- Analysis dataset structures
- Derived variable conventions
- Traceability requirements
### CDISC Controlled Terminology
**Standard coded values for CDISC variables.**
- **Link**: [CDISC CT](https://www.cdisc.org/standards/terminology)
## Format Registries
### Library of Congress
**Format documentation and preservation information.**
- **XPT Format Family**: [FDD 000464](https://www.loc.gov/preservation/digital/formats/fdd/fdd000464.shtml)
- **XPT V5 Specific**: [FDD 000466](https://www.loc.gov/preservation/digital/formats/fdd/fdd000466.shtml)
## Validation Tools
### Pinnacle 21
**Industry-standard CDISC validation tool.**
- **Publisher**: Certara
- **Link**: [Pinnacle 21](https://www.pinnacle21.com/)
Validates:
- XPT file structure
- CDISC standard compliance
- define.xml consistency
- Controlled terminology
### OpenCDISC (Legacy)
**Open-source validation (now Pinnacle 21 Community).**
- **Link**: [Community Downloads](https://www.pinnacle21.com/downloads)
## International Regulators
### PMDA (Japan)
- **Link**: [PMDA Electronic Submission](https://www.pmda.go.jp/english/review-services/electronic-submissions/0001.html)
### NMPA (China)
- **Link**: [NMPA Drug Center](https://www.cde.org.cn/)
### EMA (Europe)
- **Link**: [EMA eSubmission](https://www.ema.europa.eu/en/human-regulatory-overview/research-development/scientific-guidelines/clinical-efficacy-safety/clinical-efficacy-safety-e-submissions)
## Technical References
### IBM Floating-Point
- **Wikipedia**: [IBM Hexadecimal Floating-Point](https://en.wikipedia.org/wiki/IBM_hexadecimal_floating-point)
- **IBM Documentation**: [System/360 Principles](https://www.ibm.com/support/pages/ibm-system360-principles-operation)
### ISO 8601 Date/Time
- **Standard**: [ISO 8601](https://www.iso.org/iso-8601-date-and-time-format.html)
Used for SDTM timing variables (`--DTC`).
### Character Encodings
- **ASCII**: [ANSI X3.4](https://en.wikipedia.org/wiki/ASCII)
- **Latin-1**: [ISO/IEC 8859-1](https://en.wikipedia.org/wiki/ISO/IEC_8859-1)
## Related Tools
### xportr (R Package)
R package for XPT file handling:
- **Link**: [xportr on GitHub](https://github.com/atorus-research/xportr)
- **Docs**: [xportr Documentation](https://atorus-research.github.io/xportr/)
### pyreadstat (Python)
Python library for reading statistical file formats:
- **Link**: [pyreadstat](https://github.com/Roche/pyreadstat)
### haven (R Package)
R package for reading SAS files:
- **Link**: [haven](https://haven.tidyverse.org/)
## Citation
When referencing xportrs in academic or regulatory contexts:
```bibtex
@software{xportrs,
title = {xportrs: SAS Transport (XPT) file format library for Rust},
author = {xportrs contributors},
year = {2024},
url = {https://github.com/rubentalstra/xportrs},
license = {MIT OR Apache-2.0},
}
```