5 replies to this topic

[jman]

Sometimes table and cell size parameters perform inconsistently across browsers especially if you use cells themselves as visual borders and need a fixed width. One way to compensate for these inconsistencies is to put a single-pixel .GIF image in the cells of interest:

<td class="tmenu" width="6">
  <img border="0" src="images/dot.gif" width="1" height="1">
</td>

(I'm not sure why this works, but it does. Something to do with how IE and Netscape differ on the handling of "empty" cells.)

Is this at all problematic for search engine rankings? The reason I ask is that, as many of you know, graphics like this are embedded in a lot of spam e-mail and used by sites for tracking visitors. Hence, the use of such small graphics might be scene as potentially misleading, and search engines could penalize sites for using them. I don't know that they do, but don't want to find out the hard way.

[qwerty]

I don't think they can cause any harm, but it would be a good idea to give them all empty alt attributes (rather than none) and never, never use them as the anchor of a link.

[jman]

...and never, never use them as the anchor of a link.

Yeah, that's pretty clearly spamming.

Are you suggesting

<img border="0" src="images/dot.gif" width="1" height="1" alt="">

rather than

<img border="0" src="images/dot.gif" width="1" height="1">

Do you think the crawlers differentiate between the two?

[qwerty]

I doubt it matters to spiders, but the W3C cares:

The alt attribute must be specified for the IMG and AREA elements. It is optional for the INPUT and APPLET elements.

While alternate text may be very helpful, it must be handled with care. Authors should observe the following guidelines:

Do not specify irrelevant alternate text when including images intended to format a page, for instance, alt="red ball" would be inappropriate for an image that adds a red ball for decorating a heading or paragraph. In such cases, the alternate text should be the empty string ("").

Of course, right after that, they write

Authors are in any case advised to avoid using images to format pages; style sheets should be used instead.

But what can I say... if you can't do things exactly the way you're supposed to, I guess you should do them as close to that way as possible.

[Tenyque]

I'm not much of a web designer, but there's been three ways I've noticed that web designers "fill" the empty cell to work with older NN versions. The single pixel you proposed, the <spacer> tag, and a nonbreaking space. Anecdotally, the single pixel method seems the most prominent - with little doubt in my mind that millions of pages currently use it with no problems. If your still feeling a bit paranoid about the image you may want to look into those other two options.

[SearchRank]

As Bob (qwerty) said, 1x1 images are fine as long as you do not link them to anything. Most people use them so tables and cells can be filled in with color or background images and/or to set heights and widths. Link them to something or any image that is transparent and you risk having your pages labled as spam.