Number Formatting
ECMA-376 includes general guidelines for number formatting specifiers. MS-XLS
has a sketch ABNF grammar
Auto-Correcting Number Formats
Google Sheets and other third party writers employ number formats that are do not follow the formal grammar. Excel will transparently auto-correct them when round-tripping. Some of the known autocorrections are listed below:
Format | Correction |
---|---|
d.m |
d\.m |