Don't start or end your filename with a space, period, hyphen, or underline. Keep your filenames to a reasonable length and be sure they are under 31 characters. Most operating systems are case sensitive; always use lowercase. Avoid using spaces and underscores; use a hyphen instead.

Is it OK to use a period in a file name?

Your file names can contain apostrophes, dashes, underscores, and commas, but it is much easier to remember the rules if you use only letters and/or numbers, and avoid all punctuation. You can even use periods, but you should not put periods near the end of the file name, within the last 4 characters.

What characters are allowed in a filename?

Supported characters for a file name are letters, numbers, spaces, and ( ) _ - , . *Please note file names should be limited to 100 characters. Characters that are NOT supported include, but are not limited to: @ $ % & \ / : * ? " ' < > | ~ ` # ^ + = { } [ ] ; !

What characters are not allowed in Windows filenames?

Invalid filenames on Windows

• The filename doesn't contain any of the following characters: " (double quote), * (asterisk), < (less than), > (greater than), ? ( ...
• The filename can't end with a space or a period.
• The filename can't contain any of the names reserved by Windows.

What symbols are not allowed in filenames?

Illegal Filename Characters

• # pound. % percent. & ampersand. { left curly bracket. } right curly bracket. \ back slash.
• < left angle bracket. > right angle bracket. * asterisk. ? question mark. / forward slash. ...
• $ dollar sign. ! exclamation point. ' single quotes. " double quotes. : colon. ...
• + plus sign. ` backtick. | pipe. = equal sign.

Warning about using periods in file name

19 related questions found

What is forbidden character?

The forbidden printable ASCII characters are: Linux/Unix: / (forward slash) Windows: < (less than) > (greater than) : (colon - sometimes works, but is actually NTFS Alternate Data Streams) " (double quote) / (forward slash) \ (backslash) | (vertical bar or pipe) ? ( question mark) * (asterisk)

Why can't I use special characters in filenames?

There is no requirement to delimit the filename in any way (e.g. surround it with quotes or spaces), so encountering such a special char would cause incorrect parsing (i.e is the special char part of the filename or an operator?). <>" are reserved wildcard characters.

What characters are not allowed in Linux filenames?

Under Linux and other Unix-related systems, there are only two characters that cannot appear in the name of a file or directory, and those are NUL '\0' and slash '/' . The slash, of course, can appear in a path name, separating directory components.

Are colons allowed in filenames?

A colon is an invalid character for a Windows file name. You won't be able to allow ':' in the file name, but you can work around it.

Why you shouldn't use periods in file names?

Special characters and punctuation marks are often reserved characters for computer operating systems. This means that the character is used in a very specififc way by the operating system and using it in a file name will cause errors.

Why are there no spaces in file names?

A file system may limit the length a file can have. This was even more serious during the days when MS-DOS was limited to 8.3 filenames. So, leaving out spaces enabled you to put more meaningful characters into the name. Several other file systems also defined strict limits on their file name length.

Can directories have periods?

There are generally no issues with starting folder names with a period; however, unlike Unix and Linux environments these folders won't be hidden. To do that in Windows you need to set the System attribute on the folder.

What can I use instead of a colon?

(3) The special conditions requiring a colon are absent. Here is a famous example: It was the best of times; it was the worst of times. A semicolon can always, in principle, be replaced either by a full stop (yielding two separate sentences) or by the word and (possibly preceded by a joining comma).

What can I use instead of colon in filename?

ISO 8601 “Basic” variation. You can avoid using the colon by employing ISO 8601 “basic” format strings ( YYYYMMDDTHHMMSSZ ) for naming files and folders. The standard allows for the separators to be omitted from the YYYY-MM-DDTHH:MM:SSZ format.

What symbol is the colon?

The colon is the symbol ":". It is used in a number of different ways in mathematics. 1. To denote ratio or odds, as in 2:1 (voiced "two to one").

Can Unix filenames contain?

2020-11-15 (originally 2009-03-24) Traditionally, Unix/Linux/POSIX pathnames and filenames can be almost any sequence of bytes. ... Each pathname component (separated by “/”) is a filename; filenames cannot contain “/”.

What are the rules for naming a file?

File naming best practices:

• Files should be named consistently.
• File names should be short but descriptive (<25 characters) (Briney, 2015)
• Avoid special characters or spaces in a file name.
• Use capitals and underscores instead of periods or spaces or slashes.
• Use date format ISO 8601: YYYYMMDD.

Why are underscores used in filenames?

Answer: A: In older OSes the underscore was used in lieu of a space because the OS could not process filenames with spaces. It's a hang-over in Unix/Linux systems, particularly.

Are characters illegal?

Illegal characters are letters, numbers, punctuation marks, and similar symbols not allowed or prohibited by a computer program or syntax. ... In the Windows® operating system (OS), for example, symbols such as a colons, brackets, and question marks are typically illegal characters for use in naming files or folders.

What is special character not allowed?

You can name files using almost any character for a name, except for the following reserved characters: < > : " / \ | ? * The maximum length for a path is 255 characters. This limitation includes the drive letter, colon, backslash, directories, subdirectories, filename, and extension.

Which special characters are not allowed in passwords?

Diacritics, such as the umlaut, and DBCS characters are not allowed. Other restrictions: The password cannot contain spaces; for example, pass word .

Can you put a in a file name?

And it works the other way around too: you can't use a / in a file name with the terminal, but a : is OK and will show up as a / in the Finder.

Which characters are illegal in XML elements?

The only illegal characters are & , < and > (as well as " or ' in attributes, depending on which character is used to delimit the attribute value: attr="must use &quot; here, ' is allowed" and attr='must use &apos; here, " is allowed' ).

What are semicolon tattoos for?

“A semicolon is used when an author could've chosen to end their sentence, but chose not to. The author is you, and the sentence is your life,” explains Project Semicolon's website. ... And that's exactly what the semicolon tattoo is working to change—the stigma around suicide.