Once the charging unit is in contact it is automatically aligned against its enemy as shown in the diagram below to form a battle line. This extra alignment move is free.
If it is impractical to align a unit properly because of interposing terrain, other models, or whatever, then it is acceptable to re-align the charged unit as well (or instead) so that the battlelines remain neat. A confusing situation may arise when interposing terrain or models make it impossible to align the whole unit, for example. Rather than clutter the rules with endless clarifications we have included further examples in the back of the rulebook.