Documentation for the new filter severity settings (#107)

Also unifies documentation with facility filter and rewrite-rules.

Author: therandomstring

_includes/doc/admin-guide/options/filter-severity.md

@@ -0,0 +1,13 @@
+
+| Numerical Value | Equivalent Named Values |
+|----------------:|-------------------------|
+|               0 | emergency, emerg, panic |
+|               1 | alert                   |
+|               2 | critical, crit          |
+|               3 | error, err              |
+|               4 | warning, warn           |
+|               5 | notice                  |
+|               6 | informational, info     |
+|               7 | debug                   |
+
+Both numerical and named values are equally valid

_includes/doc/admin-guide/warnings/dotdot-stringonly.md

@@ -0,0 +1,4 @@
+
+![]({{ site.baseurl}}/assets/images/caution.png) **CAUTION:**
+The `..` notation can only be used with named values. Using it with numerical values is not supported.
+{: .notice--warning}

doc/_admin-guide/080_Log/030_Filters/005_Filter_functions/000_facility.md

@@ -18,9 +18,11 @@ You can use the facility filter the following ways:
 
 - Use a single facility code, for example, **facility(1)**
 
-- Use a facility range (works only with facility names), for example,
+- Use a facility range, for example,
     **facility(local0..local5)**
 
+{% include doc/admin-guide/warnings/dotdot-stringonly.md %}
+
 The {{ site.product.short_name }} application recognizes the following facilities: (Note
 that some of these facilities are available only on specific platforms.)
 

doc/_admin-guide/080_Log/030_Filters/005_Filter_functions/004_level_priority.md

@@ -21,6 +21,8 @@ every message of error or higher level, use the following filter:
 ```config
 level(err..emerg)
 ```
+{% include doc/admin-guide/warnings/dotdot-stringonly.md %}
 
-The [[level() filter|adm-log-filters-level]] accepts the following levels: emerg, alert, crit,
-err, warning, notice, info, debug.
+The [[level() filter|adm-log-filters-level]] accepts the following levels:
+
+{% include doc/admin-guide/options/filter-severity.md %}

doc/_admin-guide/110_Template_and_rewrite/001_Modifying_messages/002_Setting_severity.md

@@ -1,10 +1,10 @@
 ---
-title: Setting severity with the set-severity() rewrite function
+title: Setting severity with the [[set-severity()|adm-temp-severity]] rewrite function
 short_title: Setting severity
 id: adm-temp-severity
 description: >-
-    It is possible to configure the severity field with the set-severity()
-    rewrite function. When configured, the set-severity() rewrite function
+    It is possible to configure the severity field with the [[set-severity()|adm-temp-severity]]
+    rewrite function. When configured, the [[set-severity()|adm-temp-severity]] rewrite function
     will only rewrite the ${SEVERITY} field in the message to the first
     parameter value specified in the function.
 ---
@@ -21,7 +21,7 @@ rewrite <name_of_the_rule> {
 
 ## Parameters
 
-The set-severity() rewrite function has a single, mandatory parameter
+The [[set-severity()|adm-temp-severity]] rewrite function has a single, mandatory parameter
 that can be defined as follows:
 
 ```config
@@ -30,12 +30,9 @@ set-severity( "parameter1" );
 
 ## Accepted values
 
-The set-severity() rewrite function accepts the following values:
+The [[set-severity()|adm-temp-severity]] rewrite function accepts the following values:
 
-- numeric strings: \[0-7\]
-
-- named values: emerg, emergency, panic, alert, crit, critical, err,
-    error, warning, warn, notice, info, informational, debug
+{% include doc/admin-guide/options/filter-severity.md %}
 
 ### Example usage for the set-severity() rewrite function
 
@@ -54,7 +51,7 @@ rewrite {
 
 ```config
 rewrite {
-    set-severity("6");
+    set-severity(6);
 };
 ```
 
@@ -65,3 +62,4 @@ rewrite {
     set-severity("${.json.severity}");
 };
 ```
+{% include doc/admin-guide/warnings/dotdot-stringonly.md %}