Need help with line 7 of 8606

We took our first IRA distributions in December 2016 and are preparing  2016 tax forms.

In preparing the 8606 regarding the distributions we took from our individual IRA accounts I noticed that my wife’s account is categorized as a “rollover” account by my brokerage firm.

We’ve had simple/traditional IRA accounts with several different brokerage firms over three decades, and somehow when we once transferred our accounts hers got labeled a roll over.

In filling out line 7 of her 8606 the instructions say to enter the net amount but do not include rollovers. This is somewhat confusing. Are rollover distributions treated differently from distributions from other simple IRA accounts. Thanks for your help in clarifying this.