The manual for IFS follows the instructions for previous data collections closely. The present manual aggregates information that was spread across different documents: the former FSS handbook, the data suppliers manual, instructions for the production of National Methodological Reports (now called quality reports), and information available in documents presented to working groups. Differences to previous campaigns are indicated below.

Changes in classification

Figs, pomegranate, persimmons, guava and avocado

Despite the discussions farm structure working group of April 2018, where it was agreed that the figs, pomegranate and persimmons should not be considered "tropical fruit", further investigation into the issue has revealed that they should be kept as part of F2000. Figs are included in the tropical and sub-tropical fruit class, in line with the ICCFAO classification and NACE. Figs are considered a Mediterranean fruit, which are similar to sub-tropical fruit in the sense that they do not resist to extremely low temperatures and do not have strict chilling requirements for flowering and fructifying. The same applies to pomegranate, persimmons, guava and avocado.

Earth almonds

In IFS 2020 earth almond (Cyperus esculentus L.) was considered an oilseed (under Other oil seed crops n.e.c., I1190T). After further investigation, it has been reclassified as an industrial crop (under Other industrial crops n.e.c., I9000T) for IFS 2023 and following data collections. The reclassification aims to better reflect the multiple uses of this crop, which is consumed dried, roasted or raw, or used for milk ("horchata de chufa"), flour, oil, or energy production.

Other livestock n.e.c.

In previous campaigns of the farm structure survey, deer were included in this class, but in IFS they are classified separately. Also in previous campaigns there were classes for the collection of equidae. Those have been dropped and equidae for the production of meat are to be included in "other livestock n.e.c."

Livestock units

On previous farm structure surveys, ducks, geese and other poultry were considered in a unique class with a coefficient of 0.03. In IFS the classes were separated and the coefficients adjusted accordingly, with turkeys remaining at 0.03, ostriches remaining at 0.35, ducks adjusted to 0.01, geese adjusted to 0.02 and other poultry fowls n.e.c. adjusted to 0.001.

Organic animals

While in FSS only fully compliant (certified converted) animals were included, in IFS both animals under conversion and fully converted are to be included.