Comments

The {! … } tag introduces a comment. Comment tags are consumed by the parser and emit nothing to the output.

Basic syntax

{! a short note about the next block }

Data:

var person = new
{
    Name = new { First = "John", Last = "Doe" }
};

Template:

<p>Hello {Name.First},</p>{! we want to keep this greeting informal }
<p>How can we be of assistance?</p>

Result:

<p>Hello John,</p>
<p>How can we be of assistance?</p>

Multiline comments

Comment tags can span multiple lines:

{!
  Renders the customer's billing block.
  Falls back to a shipping address when billing is null.
}

Bracket handling inside comments

A comment may contain bracket characters. The parser tracks open/close pairs so that matched brackets within the comment body do not end the tag prematurely:

If a comment must contain a close brace that has no matching open brace, escape it with a backslash:

{! test comment with escaped close bracket \} }

The escaped } is emitted as part of the (discarded) comment body and does not terminate the tag.

Parser behavior

Comments are scanned by the parser and participate in MergeException line/column accounting. A misclosed comment surfaces as a parse-time error at the comment’s position.

Common uses: documenting the data shape a section assumes, explaining a ..\ walk or {#with} shift, or marking incomplete sections ({! TODO: localize }).

Whitespace

{!} accepts - trim markers ({-! … -}) and is affected by engine-level TrimWhitespace. A comment followed by a newline often produces a stray blank line in default mode — apply trim markers (or enable global trim) to suppress it.

See Whitespace Control.

Next steps

• Whitespace Control — keep comments from leaving blank lines behind
• Debugging — {@} is the diagnostic counterpart to {!}: emit content to trace listeners without affecting output