If a proper closing identifier is not found before the end of the current file, a parse error will result at the last line.

I certainly remember seeing it in The Times archive CD-ROMs in the school library when CD-ROMs were a brand new technology & being able to search all the text of last year's newspaper was an unbelievable achievement.

This doesn't pre-date TEX, but I doubt it is related to it.

instead (so the output of the command "date") In general your assumptions are wrong that quotes start with a different character than what they end with - they always have to be ended with the same as the one they have started with. the command "echo", you could also use multiple types of quotes.

At the risk of being flamed, I'd like to understand why some people prefer to use a ``construction'' of accent and single quote characters rather than the "double-quote" character when quoting things? Sorry to be so picky it's just that one seems to be from 1999 and I wonder if there are any more modern examples of this usage (it fascinates me because I've either never seen it or never paid ``attention'' to it)@Marco, I'm surprised that you haven't seen it, because I've seen it often enough to get annoyed at it.

Example: This is not command-line wizardry; I see this in written texts that are intended for humans to read. I find this construction ugly because it's asymmetrical, and because it abuses typographical characters for a purpose they weren't meant for. Unfortunately it's really, really, really hard to google for quotes, so it's hard for me to conjure up more examples...

For some reason, this use of characters is mostly (exclusively? but now that you know, you might start to notice it!

The real reason (and what may be the root cause of the La Te X usage) is that many pre-unicode unix fonts (both for the console and X), and two common Adobe Postscript encoding vectors, had typographic opening/closing quote glyphs at these positions, so , which was (especially in a proportional font where these were only 2-3 pixels wide) as close to typographically correct as you could get back then.

is series of characters, where a character is the same as a byte. Also, the identifier must follow the same naming rules as any other label in PHP: it must contain only alphanumeric characters and underscores, and must start with a non-digit character or underscore.

This means that PHP only supports a 256-character set, and hence does not offer native Unicode support. , and there may not be any spaces or tabs before or after the semicolon.