Jack Campin wrote: Then get those programs fixed.

A laughable response, and an impractical suggestion, considering that ABC development has largely been capped. My attitude toward the setups other people work with--for good reasons of their own--is not so cavalier.

Perhaps I am conditioned by writing "standard" notation--that acceptable to the concert world (and most software)--not just folk notation, and I'm certainly conditioned by using other music-writing programs that make ABC utilities seem primitive in both visual and aural rendering. They don't allow some of the "folk" conventions that some popular ABC programs will handle benignly. It's nice to know that a more relaxed, intuitive notation will work for most ABC programs, and will largely service here.

As for "normal" usage, I've found forward repeats to be seldom omitted anywhere but at the very beginning of a piece. In subsequent sections, forward repeats are almost always supplied--in modern notation, at least. In any case, it does no harm to include forward repeats as a courtesy to the performer; the "clutter" is minimal. By the way, in older music, sometimes the forward repeat is indicated by vertical dots without a leading bar line. It's often overlooked by transcribers.

JC: If you are aligning words with a tune you MUST usually start with an upbeat and end with an incomplete bar.

Lyrics alignment has nothing to do with it. You can position the syllables wherever you put the corresponding notes.

If you can make sections and repeats break with the natural phrasing, so much the better; with other systems, or for portability, you may not be able to. As for ending a piece with an incomplete bar, I think even Barfly reports this as an error, though it does the right thing. (I'm not arguing that incomplete ending bars are wrong--particularly not with circular tunes--, but both standard convention and software at large favor full bars.)

Within sections, I strongly recommend breaking lines only at bar lines, even if your programs allow mid-bar line breaks and your sources break in that manner. Besides being non-standard, mid-bar line breaks tend to throw off a performer's count, hindering more than helping. Anyway, the mapping of phrases to staff lines is arbitrary and frequently sub-optimal, particularly using default formatting settings. Better to adjust for full bars with an uncramped spacing.