Printing ascending ASCII, Cops This is the cops' thread. The robbers' thread goes here.

Write a program or function consisting only of printable ASCII characters (that excludes tab and newline) that outputs at least 5 printable ASCII characters in ascending order (from space to tilde / 32 to 126). Characters can be outputted several times, as long as they are adjacent to each other. A single trailing newline is accepted. You must provide the full output, and for every 6 characters in your code you must provide one character in your code, at the position it appears. If your code has 5 or less characters, then you have to reveal only the length. You shall not reveal more than 1 character per 6 in your code.

So if your code alphaprinter outputs the alphabet from a-z, then you need to reveal 2 characters of your code (use underscore for the others), for instance:

al__________  // or
__p__p______  // or
__________er


Rules / specifications:


You cannot append trailing white spaces that doesn't have a function.
You can not use comments (but the robbers can use comments when cracking the code)
Built-in cryptographic primitives (includes any rng, encryption, decryption, and hash) aren't allowed.
In languages where the default output are like in MATLAB: ans =, then that's accepted, as long as it's clearly stated and shown that ans = is outputted. It should also be clearly stated whether this is part of the "ascending output" or not. 
The output must be deterministic
Using a non-free language is not accepted
The output doesn't have to be consecutive characters. Both abcde and abcdg are valid outputs.
The characters do not need to be distinct as long as the output contains at least 5 characters. aaaaa and aaacc are valid.
Answers that assumes a REPL environment are not considered to be valid programs or functions and are therefore not allowed.
STDERR is not considered valid output, but data may written to STDERR.


If the revealed characters are underscores, then you must identify it as shown below. 
In this case, the second and sixth character are revealed underscores, while the others are unknown. 

_____________
 |   |


Note: The robbers only need to find a code that produces the same output. The language, the length of the robbers solution, and the position of the revealed characters must also match.

Your score is the number of characters in your code. The winner will be the submission with the lowest score that hasn't been cracked in 7 days. 
Only submissions that are posted in 2015 (UTC) are eligible for the win. Submissions that are posted later than this are welcome, but can not win.

In order to claim the win you need to reveal the full code (after 7 days).

Your post should be formatted like this (nn is the number of characters):



Language, nn characters

Output:

abcdefghijklmnopqrstuvwxyz


Code (12 characters):

al__________




If the code is cracked, insert [Cracked](link to cracker) in the header.
If the submission is safe, insert "Safe" in the header and reveal the full code in your answer. Only answers that have revealed the full code will be eligible for the win.
Perl, 46 characters (safe)

Output:

((()))*++,---../00011123445556667779::;;&lt;&lt;==??@@AAACEFGHHHIKKMMNOOOPPQQQRRSSSVWXXYY[[[\]]]^^^```aaeeffggghjjjnpppqqrttuwxxyzz{{{


Code:

print _______________________________________;


I somehow managed to delete the original in the space of a week, but I think this is right:


   print chr()x(($i=($i*41+7)%97)&amp;3)for(40..123);