---
name: "wml::sys::compat1"
section: "3"
platform: "linux"
package: "wml"
version: "2.32.0~ds1-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/wml::sys::compat1"
---

# wml::sys::compat1(3)

Backward Compatibility to WML 1.x

## NAME

wml::sys::compat1 - Backward Compatibility to WML 1.x

## SYNOPSIS

```
 #use wml::sys::compat1
```

## DESCRIPTION

Meta-HTML was used for pass 2 by WML 1.x whereas newer version use mp4h.  This include file provides backward compatibility defines for Meta-HTML tags which no longer exist in mp4h.

```
 Meta-HTML tag     mp4h equivalent tag
 ----------------- -------------------
 define-container  define-tag
 defsubst          define-tag
 defmacro          define-tag
 prog              group
 concat            group
 %%eval            group
 sub               substract
 mul               multiply
 mod               modulo
```

## AUTHOR

```
 Denis Barbier
 barbier@engelschall.com
```

## REQUIRES

P2

## SEE ALSO

[**mp4h**(1)](/mp4h/1.md)