enable additional transforms without overriding the existing ones.
- **`XMLTYPES`:**
- A white·space‐separated list of media types to consider X·M·L
- (default: `application/xml text/xml`).
+ A white·space‐separated list of media types or media type suffixes to
+ consider X·M·L (default: `application/xml text/xml +xml`).
- **`THISREV`:**
The current version of ⛩️📰 书社 (default: derived from the current
The current version of the source files (default: derived from the
current git tag/branch/commit).
+- **`QUIET`:**
+ If this variable has a value, informative messages will not be
+ printed (default: empty).
+ Informative messages print to stderr, not stdout, so disabling them
+ usually shouldn’t be necessary.
+ This does not (cannot) disable messages from Make itself, for which
+ the `-s`, `--silent` ∕ `--quiet` Make option is more likely to be
+ useful.
+
- **`VERBOSE`:**
If this variable has a value, every recipe instruction will be
printed when it runs (default: empty).