Should a sentence ending with a URL terminate with a period?

Question

Suppose my web service needs to send a password recovery e-mail message to the user. The message will contain a link (with some disposable token). Something like:

To reset your password please follow this link: http://example.com/recover/TOKEN

Now there's a problem. From the grammar point of view, a sentence must end with a period:

To reset your password please follow this link: http://example.com/recover/TOKEN.

If the message is sent in plain text or if the user is unwilling to click onto the link, but wants to copy it and paste into his browser, he might accidentally include the period into the link and that might lead to an error message from the service. Technically, it will be a user error, but it will negatively affect user experience.

So which to prefer -- a slightly illiterate phrasing or additional risk of user error?

Answer 1

The Microsoft Manual of Style for Technical Publications is quoted by Business Writing as suggesting:

1. Restructure the sentence so that the address is not at the end of the sentence.

2. Set off the address, like this, with no period (full stop):

   Please visit my website at:

   www.syntaxtraining.com

However the same site also quotes the The Chicago Manual of Style as saying:

Other punctuation marks [other than the slash] used following a URL will readily be perceived as belonging to the surrounding text. It is therefore unnecessary to omit appropriate punctuation after the URL.

I would highly recommend choosing option 1 above to remove the problem completely and also consider removing the explicit request to follow the link from the sentence - so your example becomes for example:

Don't worry, you can reset your password if you forget it.

Answer 2

It is not only a problem with copy/paste. If Thunderbird (among others) receives a plain text message with an URL, it will transform it to a clickable URL, including the end period, as it is valid in an URL. A number of other punctuation characters are also legal, so care must be used.

Tradition in such plain text messages is to surround the URL with < and > as kind of quotation marks (as the latter can be problematic too; depends on the algorithm of the URL detector): You can see that in <http://example.com/foo>.

Otherwise, as said above, a little rewording can help while preserving the elegance of the sentence (sic): You can see that in the http://example.com/foo page.

Answer 3

In this specific example, the period is not really necessary. What follows the full colon need not always be a word/ phrase or some linguistic construct. It could even be an icon/ image etc.

In general though, it is always preferable to place the link either inside the sentence or behind a part of text.

Please follow the link http://example.com/recover/TOKEN to reset your password.
To reset your password, please follow this link.
Reset your password

Please note the use of the period (and the comma).

Answer 4

You might find Grammar Girl's advice helpful:

... unless you can control exactly how the address will be rendered, it's best to leave off the terminal punctuation or rewrite the sentence so the URL doesn't come at the end.

I terminate a sentence with a period if I am writing for print. However, for online documentation, I would rephrase the sentence.

Answer 5

I guess it was in the late '90s that I learned that the "right" way to send a URL via e-mail (or on Usenet) is

preceding text <URL:http://www.example.com>.

I can't seem to find that reference now (does anyone know?) and I don't know whether that practice is still considered "right", or by whom.

I either do that, recast the sentence so the URL is not followed by punctuation (as Roger Attrill suggested), or put a space after the URL:

preceding text http://www.example.com .

The latter makes me cringe, but at least the period doesn't show up as part of the URL; but I prefer recasting the sentence (which sometimes means putting the URL on its own line as a blockquote).

Answer 6

Grammar and usage aside, DNS will accept “.” at the end of domains. “.” by itself means “root” so, for example, amazon.com and amazon.com. will both return the same DNS records.

To be sure:

Deleuze:~ ryan$ dig amazon.com. amazon.com +short | sort -nr | uniq -c
   2 72.21.214.128
   2 72.21.211.176
   2 72.21.194.1

But since you’re talking about URLs at large, I’d recast the sentence. Clarity should always trump pedantry. And besides, it’s best to end sentences with words that have an impact; URLs are mere textual flotsam… end your sentences with solid stuff.

Answer 7

I think this type of situation is a perfect use case for quotation marks. It eliminates any ambiguity as to where the URL ends and the surrounding text begins. Quotation marks can technically be used in a URL, but they'd have to be URL/percent-encoded anyways.

This is analogous to the common use of quotation marks for use-mention distinction. All the characters—including punctuation characters—inside a URL are being referrenced as characters in a URL string, not actually being used as periods, slashes, colons, etc. So putting them in quotes makes perfect sense.

It's similar to writing:

A period (".") is used to terminate sentences.

It's very obvious that the first period isn't being used as period, but is actually mentioning the character. Likewise, the following should be clear to most readers:

To reset your password visit "http://example.com/recover/TOKEN".

Alternatively, you could just put a space between the URL and the next punctuation mark:

To reset your password visit http://example.com/recover/TOKEN .

Answer 8

Why do you need to show the user the link URL in the first place? Most users would just click the link seeing blue text.

I'd vote for avoiding showing URLs at all if possible, as they break up the flow of text. Most users now know that if they really need a URL for some reason they can right click and copy it to the clipboard; those are probably the same users who would specifically need the URL for some legitimate reason.

Everyone else just wants to reset their password and will click the link. No URL necessary.

Answer 9

The problem i see is with mobile devices text selection algorithm. Some OSs will select the url as part of the sentence, selecting all the sentence, others wont, we can't know for sure. Have you considered putting the URL in a new line to increase ease of clicking/selecting? Ex:

To reset your password please follow this link:
http://example.com/recover/TOKEN

Answer 10

The URL should be followed by a space and then a period. That way humans know that it is the end of the sentence and it makes sense. Machines know that the URL does not include the period.