[css-inline-3] Define fragmentation restrictions on initial letters. #2404

Author: fantasai

css-inline-3/Overview.bs

@@ -26,6 +26,10 @@ Link Defaults: css-fonts-3 (property) font-family, css-color-3 (property) color
 At Risk: the 'initial-letter-wrap' property
 </pre>
 
+<pre class="link-defaults">
+spec:css-break-3; type:dfn; text:fragment
+</pre>
+
 <h2 id="intro">
 Introduction</h2>
 
@@ -65,7 +69,7 @@ Dominant Baselines: the 'dominant-baseline' property</h3>
 	This property specifies the <dfn>dominant baseline</dfn>,
 	which is the baseline used to align the box's text and inline-level contents.
 	It is also indicates the default <a>alignment baseline</a>
-	of any boxes participating in <a>basline alignment</a>
+	of any boxes participating in <a>baseline alignment</a>
 	in the box’s <a>alignment context</a>.
 	Values have the following meanings:
 
@@ -1180,6 +1184,33 @@ Interaction with floats</h4>
 
 	Issue: Is this the behavior we want? What if the float is on the same line as the initial letter?
 
+<h4 id="intial-letter-breaking">
+Interaction with Fragmentation (Pagination)</h4>
+
+	Since a single glyph cannot be <a>fragmented</a> across
+	pages (or columns or other <a>fragmentation containers</a>),
+	an <a>initial letter</a> is considered <a spec="css-break-3">monolithic</a> [[css-break-3]]
+	for the purpose of block-axis <a>fragmentation</a>
+	(breaking across pages, columns, regions, etc.).
+	Additionally,
+	breaks between the in-flow lines alongside an <a>initial letter box</a>
+	are avoided,
+	much as breaks between line boxes affected be 'widows' and 'orphans'
+	are avoided.
+	However,
+	if there is a <a>forced break</a>
+	alongside the <a>initial letter box</a>,
+	then it takes precedence;
+	but has no effect on the <a>initial letter box</a> itself.
+
+	As with other <a spec="css-break-3">monolithic</a> objects,
+	if an <a>initial letter box</a> occurs
+	at the top of a <a>fragmentation container</a>
+	and that <a>fragmentation container</a> is too short to contain it,
+	it may be either truncated or sliced.
+	Adjacent content, however, must be <a>fragmented</a> according to its own rules,
+	not truncated or sliced along with the <a>initial letter</a>.
+
 <h2 class="no-num" id="baseline-synthesis">
 Appendix A: Synthesizing Alignment Metrics</h2>