The Reflow SC with complete Definitions

​Tabular Data
a two-dimensional array of data points for which inclusion of a data point
within a row and column conveys meaning about the data point that cannot be
derived from the value of data point alone. Data points may be complex
objects like list, paragraphs or even nested sets of tabular data.

Perceivable Container
A document object that contains information that can be perceived by some
user of the document. A document container that is explicitly marked by the
author to not be perceived by anyone in not perceivable. Examples: An HTML
paragraph element that contains text and is not hidden can be is a
perceivable container. An element that is hidden but can be access by
aria-labelledby is a perceivable container. A pseudo-element that contains
generated text qualifies. Web components that include text or images are
perceivable containers. An HTML element that has display="none" in not
perceivable.

Partial Reading Order
Let S = {e[1],... , e[N]} be the set of all the perceivable containers of a
document. Container e[I] precedes container e[j] if and only if e[i]
contains e[j] or e[i] must precede e[J] in every logical reading of the
document.

A Proper Reading Order
Any linear arrangement, A = (f[1],... ,f[N]), of the set of perceivable
containers in a document is a proper reading order whenever the following
condition holds: If f[i] precedes f[J] in the partial reading order then
f[I] precedes f[J] comes before fJ in the arrangement, A. Intuitively, if
we read the visible elements in the order given by A, the document will
make sense.

Perceivable Object
A document object that contains information that can be perceived some user
of the document. Example: An HTML element that contains text and is not
hidden can be perceived. An element that is hidden but can be access by
aria-labelledby is perceivable.

SC Reflow
The arrangement of perceivable containers of a document in the generated
source for that document at any given time in the execution, must be a
proper reading order for the document. In addition, if all the author’s
style is removed from the document, then the document will appear as a
linear arrangement of these containers in the linear order described above.

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