[css-writing-modes-3] 7.7 Table Caption Mappings: caption-side

Hello,

"
Implementations that support the top and bottom values of the 
caption-side property but do not support side captions (i.e. left and 
right captions in horizontal writing modes) must treat both top and 
bottom as block-start, when the table is in a vertical writing mode.
"
7.7 Table Caption Mappings: the caption-side keywords
http://www.w3.org/TR/css-writing-modes-3/#caption-side
https://drafts.csswg.org/css-writing-modes-3/#caption-side

I see 2 problems with such sentence.

1-
If an implementation supports top and bottom values of the caption-side 
property but do not support side captions (i.e. left and right captions 
in horizontal writing modes), why it should not treat top as block-start 
on one hand and bottom as block-end on the other hand? Why treat both 
top and bottom as block-start?

2-
The way the sentence is written could also be subject of interpretation. 
If an implementation supports top and bottom values of the caption-side 
property, then it must do "x" regardless of its support of side 
captions. The sentence could suggest that there will be a different 
normative procedure when an implementation supports side captions... 
when there should not be any difference.

- - - - - - -


"For implementations that do support side captions (i.e. the left and 
right values from the obsolete CSS 2.0 specification [CSS2]), this 
module also introduces the inline-start and inline-end values, which 
behave similarly and which position the caption on the inline-start and 
inline-end sides of the table box, calculated with respect to the 
writing mode of the table box. For such implementations, the top and 
bottom values must place the caption on the top and bottom sides of the 
table box, respectively.
"
7.7 Table Caption Mappings: the caption-side keywords
http://www.w3.org/TR/css-writing-modes-3/#caption-side
https://drafts.csswg.org/css-writing-modes-3/#caption-side

Here, I suggest to clarify the last sentence:

Current is: (...) the top and bottom values must place the caption on 
the top and bottom sides of the table box, respectively.

Proposing: (...) the top and bottom values must place the caption at the 
logical top and logical bottom sides of the table box, respectively.

I wonder why the sentence did not just say what should have been said a 
paragraph before, which is "must treat top as block-star and bottom as 
block-end" or something similar...

Gérard

Received on Tuesday, 11 August 2015 03:45:05 UTC