[XeTeX] A feature or a bug?

[Jonathan Kew]

On 4 Jan 2008, at 5:24 pm, Lobsang Sonam wrote:

> Hi,
>
> 	I've used \char"FE3D like commands, but found only capital hex  
> numbers allowed, \char"fe3d does't work.
>
> 	Is this a feature or a bug?

That's a feature. \char expects a <number>, and one of the kinds of  
<number> TeX accepts is a hexadecimal number with the " prefix. The  
definition of <hexadecimal digit> in this context allows [0-9A-F]  
only; it does not accept [a-f].

(See The TeXbook, p.269 for the exact syntax of a TeX <number>.)

JK