Establishing a new formatting context

css-align-3/Overview.bs

@@ -915,7 +915,7 @@ The 'justify-content' And 'align-content' Properties</h3>
 <tr>
 <th>''justify-content/normal'' Behavior
 <td>
-All values other than ''justify-content/normal'' force the block container to establish a new formatting context.
+All values other than ''justify-content/normal'' force the block container to <a>establish a new formatting context</a>.
 
 For table cells, the behavior of the ''justify-content/normal'' depends on the computed value of 'vertical-align':
 ''vertical-align/top'' makes it behave as ''start'',

css-contain-1/Overview.bs

@@ -217,7 +217,7 @@ Layout Containment</h3>
 layout containment has no effect.
 Otherwise, giving an element <dfn export>layout containment</dfn> has the following effects:
 
-1. The element establishes a new <a>formatting context</a>.
+1. The element <a>establishes a new formatting context</a>.
 
 2. If a <a>fragmentation context</a> participates in <a>layout containment</a>,
 the first element with <a>layout containment</a>
@@ -352,7 +352,7 @@ Paint Containment</h3>
 <span class=note>This is as if to ''overflow: visible'' was changed to ''overflow: clip'' at used value.</span>
 2. The element acts as a containing block for absolutely positioned and fixed positioned descendants.
 3. The element creates a <a>stacking context</a>.
-4. The element establishes a new <a>formatting context</a>.
+4. The element <a>establishes a new formatting context</a>.
 
 Possible optimizations that can be enabled by <a>paint containment</a> include (but are not limited to):
 

css-display-3/Overview.bs

@@ -1055,6 +1055,28 @@ Appendix A: Glossary</h2>
 <p class="example">
 As another example, margins do not collapse across [=formatting context=] boundaries.
 
+Specifications may call for an element or box to
+<dfn export lt="establishes a formatting context | establish a formatting context | establish a new formatting context | establishes a new formatting context">establish a formatting context</dfn>
+without further precision as to the type of formatting context or how to do so.
+This operation is not applicable to
+non-atomic inline-level boxes
+nor to boxes with a layout-internal display type.
+Specifications that invoke this
+must either exclude such boxes,
+or to blockify them first.
+If the box is a block container that does not establish a BFC,
+it is made to establish a BFC.
+Otherwise, the box already establishes a formatting context, and this operation is a no-op.
+This has no effect on the computed value of the display property.
+
+Note: If a specification defines a new type of box which is neither
+non atomic inline level,
+layout-internal,
+block containers,
+or some other display type that establishes a FC,
+then that specification must define the effect,
+of invoking “<a>establishes a formatting context</a>” for that type of box.
+
 <p class="note">
 Exclusions are able to affect content across [=formatting context=] boundaries.
 (At time of writing, they are the only layout feature that can.)

css-flexbox-1/Overview.bs

@@ -638,8 +638,7 @@ Flex Items</h2>
 Its contents will however inherit styles (such as font settings) from the flex container.
 </div>
 
-A <a>flex item</a> establishes a new formatting context for its contents.
-The type of this formatting context is determined by its 'display' value, as usual.
+A <a>flex item</a> <a>establishes a new formatting context</a> for its contents.
 However, flex items themselves are <dfn>flex-level</dfn> boxes, not block-level boxes:
 they participate in their container's flex formatting context,
 not in a block formatting context.

css-grid-1/Overview.bs

@@ -1034,8 +1034,7 @@ Grid Items</h2>
 
 <h3 id="grid-item-display">
 Grid Item Display</h3>
-A <a>grid item</a> establishes a new formatting context for its contents.
-The type of this formatting context is determined by its 'display' value, as usual.
+A <a>grid item</a> <a>establishes a new formatting context</a> for its contents.
 However, grid items are <dfn>grid-level</dfn> boxes, not block-level boxes:
 they participate in their container's <a>grid formatting context</a>,
 not in a block formatting context.

css-multicol-1/Overview.bs

@@ -779,7 +779,7 @@ Spanning columns</h2>
 Content in the normal flow that appears before the
 element is automatically balanced across all columns in the immediately preceding column row before the
 element appears. 
-The element establishes a new <a>formatting context</a>.
+The element <a>establishes a new formatting context</a>.
 
 Note: Whether the element establishes a new <a>formatting context</a>
 does not depend on whether the element is a descendent of a multicol or not.

css-overflow-3/Overview.bs

@@ -383,9 +383,9 @@ Scrolling and Clipping Overflow: the 'overflow-x', 'overflow-y', and 'overflow'
 if there is overflow.
 </dl>
 
-If the computed value of 'overflow' on a <a>block box</a>
+If the computed value of 'overflow' on a box
 is neither ''overflow/visible'' nor ''overflow/clip'' nor a combination thereof,
-it creates a new <a>block formatting context</a> for its content.
+it <a>establishes a new formatting context</a> for its content.
 
 
 <h3 id="static-media">

css-rhythm-1/Overview.bs

@@ -181,7 +181,7 @@ Specifying the Step Size: the 'block-step-size' property {#block-step-size}
 Negative <<length>> values are invalid.
 
 Values other than ''block-step-size/none''
-cause the box to establish a new formatting context.
+cause the box to <a>establish a new formatting context</a>.
 
 In situations where margins <a href="https://www.w3.org/TR/CSS2/box.html#collapsing-margins">collapse</a>,
 only the box’s own margin is considered