user5653: Example:
White: Kd6, Rh6
Black: Kd8
1.?
Background story: I'm thinking of creating material for developing the visualization skills of my students. If I can convert easy problems to text notations and ask people to solve them without a chess board, I'm thinking it would be a good exercise for visualization in chess.

user12533: PGN is for game notation, i.e. the whole game. You can use the FEN notation by creating the position on chessvideos.tv FEN generator site and then use the code to input this into Fritz or your preferred software. Code is on the top right. 3k4/8/3K3R/8/8/8/8/8 is the code for the position you gave.

user1766: Just to complete the answer, you can use Fen2Ascii, a little program that converts pasted FEN lines into ASCII formatted text. From its website:

r1bqk2r/pppp2pp/2n1pn2/5p2/2PP4/5NP1/PP1NPPBP/R2QK2R b KQkq - 0 7
is changed to
W-Ke1,Qd1,Ra1,h1,Bg2,Nd2,f3,Pa2,b2,c4,d4,e2,f2,g3,h2
  B-Ke8,Qd8,Ra8,h8,Bc8,Nc6,f6,Pa7,b7,c7,d7,e6,f5,g7,h7    Black to move.


5653: <p>Example:</p>

<p>White: Kd6, Rh6</p>

<p>Black: Kd8</p>

<p>1.?</p>

<p><strong>Background story:</strong> I'm thinking of creating material for developing the visualization skills of my students. If I can convert easy problems to text notations and ask people to solve them without a chess board, I'm thinking it would be a good exercise for visualization in chess.</p>
 12533: <p>PGN is for game notation, i.e. the whole game. You can use the FEN notation by creating the position on chessvideos.tv FEN generator site and then use the code to input this into Fritz or your preferred software. Code is on the top right. <code>3k4/8/3K3R/8/8/8/8/8</code> is the code for the position you gave.</p>
 1766: <p>Just to complete the answer, you can use <a href="http://www.wmlsoftware.com/download.html" rel="nofollow noreferrer">Fen2Ascii</a>, a little program that converts pasted FEN lines into ASCII formatted text. From its website:</p>

<blockquote>
  <p>r1bqk2r/pppp2pp/2n1pn2/5p2/2PP4/5NP1/PP1NPPBP/R2QK2R b KQkq - 0 7</p>
  
  <p>is changed to</p>
  
  <p>W-Ke1,Qd1,Ra1,h1,Bg2,Nd2,f3,Pa2,b2,c4,d4,e2,f2,g3,h2<br>
  B-Ke8,Qd8,Ra8,h8,Bc8,Nc6,f6,Pa7,b7,c7,d7,e6,f5,g7,h7    Black to move.</p>
</blockquote>
