# [Tex/LaTex] newenvironment, label, indentation

environmentsindentation

I have a custom environment that I reference. It seems that the indentation changes if I do not include a space before \label (see MWE below). So, I have a few questions:

1. Should it matter where \label is placed on a custom environment; could the environment be changed so that I don't have to put a space before \label?
2. Is there a convention on where \label should be placed (on non-floating environments), or is this a matter of style?
3. Is there a preferred way of getting a line break rather than using \newline?

Please note that I do not want to use ntheorem as the actual version I use takes 2 optional arguments (using newenvironmentx from xargs).

EDIT:
I am particularly interested in trying to answer my first question- could the definition of the environment be changed so that I don't have to put a space before \label, or a % after it? The ntheorem package seems to accomplish it using trivlist.

\documentclass{article}
\usepackage{lipsum}

\setlength{\parindent}{0mm}

\newcounter{problem}
\newenvironment{problem}%
{%
\refstepcounter{problem}%
\textbf{Problem \theproblem }\newline%
}{}

\begin{document}

\begin{problem}\label{firstlabel}
\lipsum[1]
\end{problem}

\begin{problem} \label{secondlabel}
\lipsum[1]
\end{problem}
\end{document}


2. The convention is to put it after a \caption[..]{...}, or more accurately, after \refstepcounter{...} for correct labelling. Otherwise the label would refer to a previous instance of the most recent \refstepcounter{...} that was executed.
3. Use \par or \endgraf instead of \newline.