/abc = ABC. /me

public class Program
{
static void Main(string[] args)
{
string line;
Tagger tagger = new Tagger();

var sr = new StreamReader("Input.txt");

while((line = sr.ReadLine()) != null)
{
tagger.AddTag(line);
tagger.TagText(line);
}

List<TaggedText> taggedText = tagger.GetTaggedText();

var textSetByTag = taggedText.GroupBy(t => t.Tag);

Console.WriteLine("Date: {0}", DateTime.Today.Date.ToShortDateString());
foreach(var textSet in textSetByTag)
{
Console.WriteLine();
Console.WriteLine("{0}:", textSet.Key.Label);
textSet.ToList().ForEach(t => Console.WriteLine("{0}", t.Text));
}
}
}

public class Tagger
{
private List<Tag> _tags;
private List<TaggedText> _taggedText;

public Tagger()
{
_tags = new List<Tag>();
_taggedText = new List<TaggedText>();
}

public void TagText(string textToTag)
{
string regex = @"^(.*)\s*(/.*)$";

string[] matches = Regex.Split(textToTag, regex).Where(s => !string.IsNullOrWhiteSpace(s)).ToArray();

if (matches.Length != 2)
return;

//extract tag
string text = matches[0].Trim();
string code = matches[1].Trim();

//check if tag exists
Tag tag = _tags.FirstOrDefault(t => t.Code.Equals(code));

//tag text
if(tag != null)
{
TaggedText taggedText = new TaggedText(tag, text);
_taggedText.Add(taggedText);
}
}

public void AddTag(string tagExpression)
{
string regex = @"^(/.*)\s*=\s*(.*)$";
//extract code and label
string[] matches = Regex.Split(tagExpression, regex).Where(s => !string.IsNullOrWhiteSpace(s)).ToArray();

if (matches.Length != 2)
return;

string code = matches[0].Trim();
string label = matches[1].Trim();

Tag tag = new Tag(code, label);

_tags.Add(tag);
}

public List<TaggedText> GetTaggedText()
{
return new List<TaggedText>(_taggedText);
}

public List<Tag> GetTags()
{
return new List<Tag>(_tags);
}

}

public class TaggedText
{
public TaggedText(Tag tag, string text)
{
if (tag == null)
throw new ArgumentNullException("tag");

Tag = tag;
Text = text;
}

public Tag Tag { get; private set; }
public string Text { get; private set; }
}

public class Tag
{
public Tag(string code, string label)
{
if (string.IsNullOrWhiteSpace(code))
throw new ArgumentException("Code cannot be empty");
if (string.IsNullOrWhiteSpace(label))
throw new ArgumentException("Label cannot be empty");

Code = code;
Label = label;

}

public string Code { get; private set; }
public string Label { get; private set; }
}

import collections
import datetime
import sys

Section = collections.namedtuple('Section', ['tag', 'name', 'lines'])
sections = []

for line in map(str.rstrip, sys.stdin):
if line.startswith("//"):
continue # skip a comment
elif line.startswith("/"): # define new section
tag, name = line.split(" = ")
sections.append(Section(tag, name, []))
else:
for s in sections:
if line.endswith(s.tag):
s.lines.append(line[0:-len(s.tag)])

print("Date: {}".format(datetime.date.today()))
print()
for s in sections:
if s.lines:
print("{}:".format(s.name))
for l in s.lines:
print(l)
print()