@Puzzler : A linea is a hanjie with a special rule : each line or stroke is never larger than 1 square. So you can't have such figures as a square 2x2 or a "T"... There's not so much specific methods to solve them except the fact that, on every line longer than 3 squares blackened, you can put crosses on each side of the squares blackened that are not on the beginning and the end... I hope it will helpful for you to solve them.

@Puzzler : By example, on this hanjie, the 8-line in column 25 can't be anywhere else than from line 16 to line 23 because elsewhere it would create squares 2x2 or "T" figures.
I forgot to say that there is a little difference between linea and linea+ (not always called like that but often linea also) : a real linea is made of only one line when a linea+ is made of several lines, eventually that are circuits. The most often, the number of lines (and number of circuits) are written in the description.

@Puzzler : Yes, you're right, no "T", no "+", but "U" and "L" are possible.