Like other inline passthroughs, the inline pass macro can be used to control the substitutions applied to a run of text.
To exclude inline content from all of the substitutions, enclose it in the inline pass macro.
For example, here's one way to format text as underline when generating HTML from AsciiDoc:
Here's one way to format text as underline when generating HTML from AsciiDoc:
[source]
----
include::example$pass.adoc[tag=in-macro]
----
And here's the result.
====
include::example$pass.adoc[tag=in-macro]
====
WARNING: Using passthroughs to pass content (without substitutions) can couple your content to a specific output format, such as HTML.
In these cases, you should use conditional preprocessor directives to route passthrough content for different output formats based on the current backend.
WARNING: Using passthroughs to send content directly to the output can couple your content to a specific output format, such as HTML.
To avoid this risk, you should consider using conditional preprocessor directives to select content for different output formats based on the current backend.
What sets the inline pass macro apart from the alternatives is that it allows the substitutions to be customized.
The inline pass macro also plays a critical role in the document header.
In fact, it's the only macro that is processed in the document header by default as part of the xref:subs:substitutions.adoc#header-group[header substitution group] (though it can be used to enable other substitutions, as demonstrated in this section).
Let's look at how to use the inline pass macro to hand select substitutions.
=== Custom substitutions
You can customize the substitutions applied to the content of an inline pass macro by specifying one or more substitution values in the target of the macro.
Multiple values must be separated by commas and may not contain any spaces.
The substitution value is either the formal name of a substitution type or group, or its shorthand.
The following table lists the allowable substitution values:
.Substitution values accepted by the inline pass macro
[cols="1m,3m",width=50%]
|===
|Shorthand | Substitution Type
|c
|specialchars
|a
|attributes
|r
|replacements
|m
|macros
|p
|post replacements
h|Shorthand
h| Substitution Group
|n
|normal
|v
|verbatim
|===
For example, the quotes substitution (i.e., `q` or `quotes`) is enabled on the inline passthrough macro as follows:
The inline pass macro is the only macro that is processed in the document header as part of the xref:subs:substitutions.adoc#header-group[header substitution group].
[source]
----
include::example$pass.adoc[tag=in-macro-sub]
----
Here's the result.
====
include::example$pass.adoc[tag=in-macro-sub]
====
To enable multiple substitution groups, separate each value in the macro target by a comma:
